Chapter 1: Accounts and Registration

1.1 Getting Started (An Introduction)

Complete: 5
Detailed Review status

In this chapter we cover initial information about getting set up with computing accounts and basic tools so that you’re ready to run the tutorials in this Workbook. We cover:

  • Discussing the computing concepts (WorkBookComputingConcepts) that you are assumed to understand before going through the Workbook, e.g., Linux, C++, CVS, ROOT. Don't miss the appendices (at the end of the Essentials part of the Workbook, after chapter 5); they can help you get up to speed on some of these concepts.

  • Providing pointers to information resources (WorkBookHelp) beyond the Workbook. Find out about software reference material, meetings, hypernews forums, CERN and CMS-specific web pages, and more. The Workbook doesn't stand alone in the world of CMS-related information!

Review status

Reviewer/Editor and Date Comments
JennyWilliams - 26 Sep 2007 General tiding

This page is complete and clear: relevant information, ok; instructions work and clear, ok; links, ok. Antonio Morelos 120423

Responsible: SudhirMalik
Last reviewed by: Main.scarletnorberg- 1 December 2015

1.2 Getting a Computing Account

Complete: 5
Detailed Review status


Getting a CERN Account

You must get a CERN computer account (also called a SSO i.e. SingleSignOn account).

All CMS collaborators are eligible for a CERN Unix account (often called lxplus or afs account) and a CERN email account (often called a nice account), and are entitled to use CERN computing resources.

Currently CERN has a single account for all those services (also called SSO i.e. SingleSignOn account).

Register as CERN User

Remote computing CERN account only:

People who will NOT come to CERN and just need a CERN computing account register as "External people participating in an experiment" (PART). You will work with the CMS Secretariat to initiate your registration, starting with this CMS form for CERN account. Your responsible may always fill out the PRT later (below) for CERN access, be sure to do it well before your trip.

NOTE: Without a valid passport as an ID, one cannot register as a USER. In the absence of a passport, CERN will accept US and Canadian driver's licenses in the same manner as national ID cards for the registration of External Participants.

Make sure you are registered as a USER and NOT as VISITOR or EXTERNAL. Only a USER status will give you access with all computing privileges and resources to work like grid certificate, CMS twikis (internal twikis requiring login), indico, hypernews etc.

Intend to go to CERN and need accounts:

COVID-19 NOTE: "In the context of the COVID-19 situation, PRT will not be processed until further notice. For remote access please contact your Experiment Secretariat.". Please contact the CMS Secretariat to register new remote CERN users with CMS. For updates on this policy: see During the COVID-19 situation, you will fill out the Remote computing CERN accounts access only (instructions just above), and submit the PRT form once CERN opens up again.

Your responsible (for users, Team Leader, Group Leader of the institute and for COAS and VISC the Department Head or an authorized person on his/her behalf) has to initiate the online registration via the Pre-Registration Tool PRT. Note that if a user NEVER intends to go to CERN do not use the PRT tool for remote computing accounts.

Make sure you are registered as a USER and NOT as VISITOR or EXTERNAL. Only a USER status will give you access with all computing privileges and resources to work like grid certificate, CMS twikis (internal twikis requiring login), indico, hypernews etc.

NOTE: Without a valid passport as an ID, one cannot register as a USER. In the absence of a passport, CERN will accept US and Canadian driver's licenses in the same manner as national ID cards for the registration of External Participants.

After CERN registration

Once you are registered in the CERN Human Resource database, your Primary CERN Account, CERN e-mail address & mailbox are created automatically. Since you are registered with CMS Experiment, you will get an email from with instructions about next steps.

You can read some more info here.

NOTE: Information given below is useful AFTER you get registered at CERN and have a CMS computing account.

lxplus (afs)

To access Linux interactive farm use



To access the NICE/windows services you can go to


You can set up the mailserver from

Your e-mail address will be of the general form (GEM) "" which is an alias normally pointing to your e-mail box (PEM) "". The following conventions apply:

  • If a second initial (or name) is included in the e-mail address, it is separated by dots.
  • If the name consists of separate parts, a dot is used between the parts, instead of a blank.

Administrative Information Services (ais, edh)

You can access the Administrative Information Services (ais) and the applications therein (such as edh: Electronic Document Handling System) with your common password. To login into edh go to A separate edh signature password is needed to accept or reject edh documents. You acquire this password from (remove SPAMNOT) and it can be changed on the edh page where "settings" and "authorisation password" are.

The edh signature password is needed also for acquiring access rights to radiation or underground areas. You may also need extra safety courses ( as well.

There are several courses. The lowest safety level course and computer related course are required to perform activities on the CERN site(s) and access CERN Computing system. As part of the CERN registration you will be asked to go through those courses.

Further information

Here are standard instructions for learning about and getting these items:

Getting a CMS HN account

You will need a CMS HyperNews account, this can only be obtained once you have a working CERN computer account by following these instructions here. Please note that when you do the ssh step, you have to use your CMS related CERN account (the one in "zh") and your normal CERN password. Then follow the instructions as given.

Getting a Local Account at your Institution

You may also have access to computing resources at your local institution. You should ask your local computing experts and colleagues about the use of these resources for CMS-related work. See WorkBookRemoteSiteSpecifics, to see if your institution has provided information.

FermiLab Special for Fermilab: WorkBookRemoteSiteSpecifics#FermiAccount

Access to AFS and CMS Software

The WorkBook instructions generally assume you're running CMS software on the CERN Public Login Linux system LXPLUS. This environment ensures that you will have direct access to the AFS file system, which holds the CMS software Releases. Additionally, all the tools you'll need to develop your software are installed and set up on LXPLUS , so you can start work almost immediately. Local systems may have different unix shells and different setups, it is impossible to provide fool-proof instructions for all environments. Again, see WorkBookRemoteSiteSpecifics, to see if your institution has provided information. If you are not familiar with using Linux, see this list of basic Linux Commands.

Access to the Grid

See Starting on the GRID, Grid Basics.

Review status

Reviewer/Editor and Date (copy from screen) Comments
SudhirMalik - 09-Sep-2017 Responsible
MargueriteTonjes - 01-Sep-2017 Responsible

This is an example how to add you detailed comments. Use the usual twiki syntax (see Edit help in the twiki edit mode).

The information is relevant and clear (only one sugestion to add a sentence), some links require little work. Antonio Morelos 120424

I would suggest to change the link " " to something like: " (remove SPAMNOT) "

I would suggest to change the tel. number " +41227678888 " to something like: " +41227677777 " As shown in page

I would suggest to change the link " " to something like: " (remove SPAMNOT) "

I would suggest to change the address " " to something like: " " As shown in page

I would suggest to change the address " " to something like: " (remove SPAMNOT) "

In the subsection "Adminstrative Information Services (ais, edh) I would suggest to include the following text: " There are several courses. The lowest safety level course and computer related course are required to perform activities on CERN site(s) and access CERN Computing system. As part of the CERN registration you will be asked to go through those courses. "

I would suggest to update the link at " Use of CERN Computing Facilities ", presently points to " " which it redirects itself to: " "

I would suggest to update the link at " CERN Computer Security Information " presently points to " " which it redirects itself to: " "

I would suggest to update the link at " If You Need Help (IT service) " presently points to " " this page does not exist, instead the automatic search is sent to: " "

Inserted the suggested comments and checked them , Antonio Morelos 120425

Make it clear CERN account is now mandatory, refer to SSO, add HN acount, rename Grid Certficate to Access to Grid , Stefano Belforte 121114

Responsible: CMSUserSupport
Last reviewed by: Main.Sudhir Malik - 9 Sep 2017

1.3 Your Computing Environment

Complete: 5
Detailed Review status

Goals of this page:

After following the instructions on this page you should have your working environment ready to run tutorials and examples.



The tutorials and examples in the workbook may be done on the CERN UNIX cluster LXPLUS or on any other machine or cluster that has CMSSW installed. The instructions on this page assume that you already have a CERN account; if not, see WorkBookGetAccount. Grid computing comes a little later; see WorkBookStartingGrid for information on that.

CMSSW Software Installed at a Generic Site

CMSSW does not need to be installed locally at every site. Users can access it via the LXPLUS cluster at CERN or at some of the T1 centers. For sites that wish to install it locally, installation instructions are beyond the scope of this workbook, and can be found on this page Installing software using apt.

If you are using a local installation, you may need to use slight variations of the standard instructions in this workbook for some tasks. Any variations should be documented in the workbook page Specific Information for Remote Sites and Institutions. If not, please contact your system admin and ask that the necessary information be added or links provided.

Log in to the CERN UNIX Cluster

We'll assume you want to run CMSSW on the the LXPLUS cluster at CERN. AFS is installed on this cluster, so your home area is your AFS home area in Instructions for other remote systems may be found at Specific Information for Remote Sites and Institutions.

If you are connecting remotely, you'll need an X connection to view output.

To log on, use ssh:

ssh <username>

You should automatically obtain your CERN kerberos credentials; if not, use the AFS kinit program (in /usr/sue/bin) with your CERN AFS password to authenticate to the CERN Kerberos 5 server.

Log in at remote sites

Instructions for other login platforms can be found in Specific Information for Remote Sites and Institutions.

Create a work area and build the application

We will be using CMSSW (currently at version CMSSW_9_2_3) as the application and SCRAMv1 as the build tool. If you are not familiar with SCRAMv1, you might want to look at WorkBookScramV1Intro.

Build the work area

First execute the following commands to access CMSSW repository:

setenv VO_CMS_SW_DIR /cvmfs/

source $VO_CMS_SW_DIR/cmsset_default.csh

Then verify that CMSSW release CMSSW_9_2_3 is installed on your system.
scram list -a | grep CMSSW_9_2_3

If installed, it will return a pointer of the form /cvmfs/ or /cvmfs/ depending upon whether the SCRAM_ARCH is set to slc6_amd64_gcc530 or slc6_amd64_gcc630.

Some common errors:

  • If you get the error message scram: command not found on lxplus, it is likely that you are not registered as a CMS user. Follow the instructions on how to get a CMS account so that some settings are done automatically when you login.

To build the work area, go to your work directory (often ~/scratch1) and type

cmsrel CMSSW_9_2_3

This is equivalent to the full command scramv1 project CMSSW CMSSW_9_2_3

You will now have your developer area under a new CMSSW_9_2_3 directory. For instance, at CERN, the developer areas look like the following:


Setup your runtime environment

You must setup your runtime environment every time you start work in your project area.

cd CMSSW_9_2_3/src

To setup the runtime variable do


This is equivalent to the longer command, for a csh varient shell (csh, tcsh)

eval `scramv1 runtime -csh`

or if your shell is a sh varient (bash, zsh)

eval `scramv1 runtime -sh`

Set up GitHub

CMSSW code that you will need to access is maintained in a GitHub repository. We describe how to use this in GitHub in section CMS Computing Concepts.

Set up ROOT

To learn about ROOT, see ROOT Basics or the ROOT homepage. ROOT automatically loads all the necessary CMS-specific libraries (shell prompt shown for clarity):

$ root -l              #the -l, lower case L, is optional, and if used, omits the logo

SSH, X11 forwarding and opening windows to remote machines: Windows

Often you'll need to open xwindows applications from a PC - e.g. to run the CMS event display, or more regularly to run a ROOT session. Both these tasks tend to require you to connect from a Windows or Mac PC to a linux machine (generally using ssh), and then to have windows from the ssh session pop up to display graphics.

The general process for this: start an ssh connection from your windows/mac machine into a linux system(e.g. CERN lxplus) and then start the xapplication. Note that you have to enable the X11 connection (in PuTTY, select Connection -> SSH -> X11 in the left bar and check the corresponding box). To enable the graphics windows to appear, you'll need to have an X11 server running on your PC, and also to have an ssh client which supports X11 forwarding. It's not that frightening...

To do windows X11 forwarding, you need an X Server for Windows (e.g. Cygwin/X, xwin32, Xmanager, etc.) and an SSH client that supports X11 forwarding.

Some good SSH clients are:

  • PuTTY is an SSH client and WinSCP is a companion SCP program for secure file transfer in Windows. Both are available from CERN (the links will point you to the correct folders) where you will log in using your CERN NICE account.
  • Secure Shell (SSH) is a simple, easy-to-use SSH client that comes with SFTP so you don't have to download a separate program for secure file transfer in Windows.
There are various choices of X Servers for Windows:
  • Xming server. Small, fast and easy. If you do not want to install the Font Package, you can run XLaunch (part of Xming) to set the font server:
  • Cygwin/X11 server has a good integration with the Windows desktop.
  • Hummingbird Exceed is a commercial product used by CERN, and it's available for installation on NICE computers.
  • Starnet xwin32 is another commercial product used by many US university groups. While it can be used for 30 days on a free trial, more prolonged use requires a license.
  • Similarly, Xmanager has a free 30 days trial period, and then costs about US$100 to keep using.
For a simple, free and fast setup, all you need are an SSH client and Xming to log into a Linux machine from a Windows desktop. Remember to set SSH to allow X11 tunnelling and you can work straightaway.


Often the linux machine you want to run applications such as ROOT on is far from the PC you are using - e.g working in the US using a CERN lxplus machine. Then X11 is often a bad choice for graphics, as X11 was not designed to work over high latency connections (hence can get very slow responses). Using VNC over ssh rather than X11 can avoid the problem of remote access. However, the default Windows Manager twm that you get with VNC is difficult to use. If you start up Gnome or KDE when you log in through VNC, then the connection becomes slow, which defeats the purpose of using VNC in the first place. If you are only running programs on a remote computer that require little user interaction, then VNC is fine. If you are doing a lot of interactive work, then VNC is not suitable. Note that the VNC protocol is not encrypted, so you must set up a secured connection through SSH. Also, please read this security message by CERN IT.

Remote Desktop

Perhaps the best solution for a user across the ocean to work on a CERN lxplus machine is to connect to cernts (CERN Windows Terminal Services) either through Remote Desktop Connection (for Windows and Mac OS), or through rdesktop (for Linux OS). From the web site, register to use the service and follow the instructions to connect to cernts. Once connected, go to the Start menu and look for the program Hummingbird Connectivity 2007 → CERN Predefined Connections for TS → lxplus (SLC5). Running emacs will be almost as fast as running it from a local machine.


Sierra (10.12) and High Sierra (10.13) are stricter about X forwarding compared to older Mac systems. Use:

ssh -Y <username>

This option enables "trusted" X11 forwarding and will allow you to open ROOT and the TBrowser without any problem.

Get CERN Kerberos ticket

If you are onsite at CERN, you should get your Kerberos ticket normally. When you login on LXPLUS you get a ticket which is valid for 25 hours, if you stay logged in for a longer time, you can renew it with command


and typing your LXPLUS (afs) password.

If you are running jobs from an offsite location, but accessing files or resources at CERN, you will need to obtain CERN Kerberos credentials. To get valid CERN Kerberos credentials, run:

kinit @CERN.CH

It will ask for your LXPLUS login username and password. You can safely transmit them over the network.

Working with large files

The storage of the output data is explained in page WorkBookUsingT2Resources#StoreDataOutput.

Locally at CERN, if your personal working area on CERN's LXPLUS cluster isn't big enough to handle your output files, you'll need to write them to a larger-capacity area. To ask for "AFS workspace" (up to 100 GB, backed up), login to the Cern account web page and go to "Applications and Resources", take the "Manage"-link next to "Linux and AFS". There you can ask for "workspace" in AFS, as well as extend the quota for your backed-up $home (up to 10 GB). Please note the different AFS path to your workspace: /afs/ where initial is the first letter of your username, i.e. the workspace is not hanging from your $home. For other sites, see WorkBookRemoteSiteSpecifics.

Working with several large files

The area AFS "workspace" is usually not enough for running or storing output of several jobs at the same time. In such a case CERNBox/EOS area prove to be extremely useful. The conventional use of CASTOR is now discouraged.


CERNBox provides cloud data storage to all CERN users. You can store your data, share it and synchronise it across devices - smartphones, tablets, laptops, desktops, the lot! One has to register to CERNBox by connecting to website: The data can be accessed from any Web browser or file explorer, and you decide which data you want to share with other individuals or groups of collaborators. Data can be synchronised to your devices (Windows, Mac, Linux, iOS and Android) with the CERNBox application.

Accessing your CERNBox files stored in EOS on lxplus

CERNBox files are stored in the EOSUSER instance. To access your files from lxplus you can use standard unix commands: e.g. ls /eos/user/initial/username

In order to transfer files, you should set up your environment:

Set up the variable EOS_MGM_URL:

export EOS_MGM_URL=root:// (for bash) setenv EOS_MGM_URL root:// (for tcsh)

The XRootD/EOS entry point (instance server) for your files in CERNbox is root:// and your user directories are under /eos/user/initial/username.

NOTE: if you are using EOS for both CERNBox and your experimental/analysis work, be sure to verify which instance of EOS you are querying when running EOS commands. One way to force an EOS command to query a specific instance is to specify the server for that instance:

eos (instance server) (command)

E.g. to list xyz's files in CERNBox: eos root:// ls /eos/user/x/xyz and to query EOSCMS: eos root:// (command).

More details can be found at: CERN EOS Twiki.

Using Castor (Not recommended)

Another method (which is now discouraged) is to store on CASTOR. The CASTOR Project stands for CERN Advanced STORage Manager, and its goal is to handle LHC data in a fully distributed environment.

Every user with CERN account has a directory in CASTOR. To list the files in your directory, type

rfdir /castor/

where initial is the first letter of your user name. You can create directories with

rfmkdir /castor/

and you can copy files to a castor directory with

rfcp filename /castor/

The output file can be saved to CASTOR by using the following script called runMyJob.(c)sh

cd /afs/
eval `scramv1 runtime -(c)sh`
cd -
cmsRun /afs/
rfcp outputFile.root /castor/

The batch job starts to run in a directory called /pool/lsf/username/jobnumber, and this directory has a large scratch space that is available for the duration of the job. You then cd to scratch1/CMSSW_9_2_3/src/.../.../test to set the environment variables. The command "cd -" takes you back to /pool/lsf/username/jobnumber so that the large scratch space is available. aConfigFile.cfg is run from that directory, and the last line copies the output root file from there directly to your space in CASTOR. Note that while writing directly to a file in CASTOR is possible, it is not recommended, as it is very error-prone. The recommended practice is the one indicated above, i.e. writing to a local area and copying the file after cmsRun has finished.

You submit the job in the same way as that for smaller jobs.

bsub -q 1nd -J job1 < runMyjob.(c)sh

It is also possible to request a minimum amount of space in /pool/lsf/username/jobnumber using the -R option, for example to request a minimum of 30GB type

bsub -R "pool>30000" -q 1nd -J job1 < runMyjob.(c)sh

Opening files from CASTOR (Not recommended)

To open a file in an interactive root session, type

TFile *f  = TFile::Open("rfio:/castor/")

If you want to use a file saved in CASTOR as input to a CMSSW job, add the following to the .cfg file

source = PoolSource{ untracked vstring fileNames = {'rfio:/castor/'} }

See the lxbatch introduction pages: and the CASTOR web page for further information. Some advice in case of trouble with data access is given in the Troubleshooting guide.

UserCode area in GitHub

With the move from cvs to git, there is no longer any central UserCode area. Instead, users are encouraged to create their own github repository to store and share their own personal code. You can put any code you want in your own repository.

If instead you want to put code in the central cmssw repository, the process is more complicated. For instructions on developing official cmssw code, see the tutorial.


Set up CMS Environment:
If you're using the LXPLUS cluster at CERN, the CMS environment is set up by default at login time.

For remote systems you'll need to set up the CMS environment explicitly. This is site-specific. To find out how to setup the CMS environment other remote sites; see Specific Information for Remote Sites and Institutions or your sysadmin.

ONLY if not done previously, create your work area (do this only once per CMSSW version, not every login session):

cmsrel CMSSW_9_2_3

Set your runtime environment:
cd CMSSW_9_2_3/src

Review status

Reviewer/Editor and Date (copy from screen) Comments
NitishDhingra - 12 Nov. 2017 Added information on CERNBox/EOS.
NitishDhingra - 29 Oct. 2017 Updated to CMSSW_9_2_3, removed outdated info, fixed broken links etc.
XuanChen - 30 May 2014 added command of setting an environmental variable, replaced the link of SSH, changed the part of usercode and replaced CVS by github
JohnStupak - 4 June 2013 revised and updated to CMSSW_5_3_5
AndreasPfeiffer - 15 Dec 2009 update login part (kerberos 5 now) and Mac part (all OS versions above 10.4)
KatiLassilaPerini - 08 Jul 2008 replaced scram commands with cmsrel and cmsenv, removed project CMSSW
AndreasPfeiffer - 11 Feb 2008 update statment on (obsolete) slc3
AndreaBocci - 10 Jan 2008 reflect change in Xming licensing terms
AndreaBocci - 26 Jun 2007 different definitions of free
MarkoDragicevic - 11 Jan 2007 added Xming to suggested X servers
KatiLassilaPerini - 29 Sep 2006 added more CASTOR from Nick Grant
KatiLassilaPerini - 10 Oct 2006 added UserCode in CVS
JennyWilliams - 29 Nov 2006 added notes about X11 forwarding

I went through chapter 1 section 3, the information is relevant and clear, this page has several links out off date.

Several links require just to update the link (email from morelos to Kati).

For the four links at the bottom of this comment, I could not relate a link.

best regards, Antonio Morelos

I would suggest to update the link at " Installing software using apt "

I would suggest to update the link at " PuTTY "

I would suggest to update the link at " WinSCP "

I would suggest to update the link at " Xmanager "

I would suggest to update the link at " secured connection through SSH "

I would suggest to update the link at " security message "

I would suggest to update the link at " CERN Windows Terminal Services "

The link at " Secure Shell (SSH) " It is sent to a "Not Found" page. I could not find a clear option on what to suggest concerning this link. I guess the intention is to click-download the exe file ?

The link at " SnowLeopard " The link goes to the twiki editor. I could not find a clear option on what to suggest concerning this link. Is the intention that the explanation text is missing ? or is the intention to sent the user to the SnowLeopard MacIntosh Page ?

The link at " " Which confuses myself on what should I see on that page, related to " See the lxbatch introduction pages: "

The link at " UserCode/README " which confuses myself on what sould I see on that page, this page does not look like an instruction page.

Updated the straightforward links that A.Morelos suggested.

Responsible: SudhirMalik
Last reviewed by: AndreasPfeiffer - 11 Feb 2008

1.4 CMS Computing Concepts: Programming, GitHub, etc

Complete: 5
Detailed Review status

Goals of this page

You will learn what programming language(s) you are expected to know, what software packages you should be familiar with, and how to access software from the code repository.

Note that in 2013, the CMS software repository was moved from CVS to git. CMS no longer uses CVS. The new git software repository is hosted at a website called GitHub, which provides extra features beyond git's file version control.


Operating Systems

Familiarity with Linux is necessary. Current versions of the CMS Offline software, CMSSW, run on Scientific Linux CERN 6 (SLC6) (which is built on Scientific Linux 6 (SL6), which is in turn built on Red Hat Enterprise Linux 6 (RHEL6)). Run I (2010-2012) was based on SL*5. The upgrading process, from SL*5 to SL*6, started in 2014 with the 7_0_0 release. Currently for Run II analyses the release being used is CMSSW_9_4_2.

Programming Languages

CMSSW code is written in C++. You will need to be able to write compatible code in C++. There are many good text books available. See Walter Brown's (of FNAL) book recommendations for C++ Programmers :

Analysis Packages

You will need to know how to use ROOT. It is an object-oriented data analysis framework.


CMS software, including CMSSW, is now maintained in a GitHub software repository. You'll need to use GitHub to check out code and configuration files to your area so that you can modify and use them. There are lots of working examples in GitHub for you to try; various workbook tutorials point you to specific directories. Since CMSSW is such a large project we use the sparse check-out features of git. Because of this it is highly recommended that you look at the CMS git tutorials to understand how this is done.

Here we give instructions on checking out code from GitHub. When you are working in the CMS environment, you can run any of the CMS code in the release without checking it out. You only need to "check out" code that you need to modify, code that has been modified by someone else, or code that depends on modified code. Then that code can be rebuilt.

A "release" is a set of software which has a version number and has been thoroughly tested to all work together. The CMS code evolves with stable, working releases numbered and advertised from time to time as a recommended set of code to use.

Git Documentation

The primary documentation for usage of git in CMS is at the following locations:

The information located there is much more detailed and complete as compared to the information listed below.

(Warning: Early in the introduction of git into CMS, CMS created a thing called the Topic Collector which some documentation still references. The Topic Collector is no longer used for any purpose. GitHub directly offers features that replace that functionality and now we use them. If you see references or links to the Topic Collector, you should understand you are looking at obsolete documentation that needs to be updated.)

Obtaining a personal GitHub account:

If you want to modify code and then have your modifications merged into the official repository of CMSSW code, you will need a personal GitHub account. You would first edit the code and commit it to a git repository on the machine where you work (maybe the machine on your desk or lxplus). Then you would push the changes to the repository in your personal GitHub account. Then you would issue a pull request to have the modifications pulled from your personal GitHub repository to the official CMSSW GitHub repository by a release manager.

A personal GitHub account has other uses. It is also a useful way to send your code modifications to other people or groups. It can also be used as a way to backup code modifications that you make and maintain version control of your own personal code.

But a personal GitHub account is only mandatory if you want to merge code into the official CMSSW code repository. You can download code, build it, and run it locally without a personal GitHub account.

First you have to obtain a GitHub account. Go to and follow the instructions to open a new account if you do not already have one.

Then fork the official CMSSW repository. That creates a copy of it in your personal GitHub account. Fork by going to and click on the fork button and follow the instructions. After the forking is done you see you have a new repository cmssw,<your-username>/cmssw.

Setup personal information

  • Login on lxplus at CERN or wherever you plan to do your code development work.
  • Run the following commands:
    • git config --global "First name Last name"
    • git config --global <Your-Email-Address>
    • git config --global user.github <Your-Just-Created-GitHub-Account-Username>

Easy access of GitHub (optional)

  • If you have no ssh key: Follow generating-ssh-keys on GitHub to create a ssh key.
  • If you have already an ssh key: Login to GitHub -> settings -> SSH keys ( and add your key. I.e. copy paste the content of
  • To use your key you have to execute following commands after each login:
    • eval $(ssh-agent); ssh-add /path/to/your/key
  • Test your configuration: ssh -T
    • You should see: Hi XYZ! You've successfully authenticated, but GitHub does not provide shell access.

Checkout a CMSSW package from Git

  • Setup a CMSSW environment
cmsrel CMSSW_9_4_2
cd CMSSW_9_4_2/src

  • Checkout a package, e.g. PhysicsTools/PatExamples
git cms-addpkg PhysicsTools/PatExamples
No release tags specified, using default CMSSW_9_4_2.
You are on branch from-CMSSW_9_4_2
Checking out packages
  • Create your own development branch e.g. mydev
git checkout -b mydev
Switched to a new branch 'mydev'
  • Check which branches are available
git branch
* mydev
  • Apply modifications
echo '#modfication' >> PhysicsTools/PatExamples/BuildFile.xml #this adds a line containing #modification at the end of BuildFile.xml
  • Check if modification is recognized
git status
# On branch mydev
# Changes not staged for commit:
#   (use "git add <file>..." to update what will be committed)
#   (use "git checkout -- <file>..." to discard changes in working directory)
#       modified:   PhysicsTools/PatExamples/BuildFile.xml
no changes added to commit (use "git add" and/or "git commit -a")
  • Add and commit your changes
git add PhysicsTools/PatExamples/BuildFile.xml
git commit -m "test message"
[mydev 6812826] test message
 1 files changed, 1 insertions(+), 0 deletions(-)
Your modifications were commited to your local git repository. You can push these changes to your personal GitHub repository with the following command.

git push my-cmssw mydev

Before you do this you will have to have already created your personal GitHub account and forked the cmssw repository. (Creating and forking are one time actions. They do not need to be done with every push, see above for more information).

If obtain this message:

ERROR: Repository not found.
fatal: The remote end hung up unexpectedly
git wasn't able to find the my-cmssw repository in you GitHub account. Check if you forked the repository. If the push is successful you see:
Counting objects: 9, done.
Delta compression using up to 16 threads.
Compressing objects: 100% (5/5), done.
Writing objects: 100% (5/5), 436 bytes, done.
Total 5 (delta 4), reused 0 (delta 0)
 * [new branch]      mydev -> mydev
You visit your account at GitHub and click on the branches drop-down menu you see your new branch mydev. Inspect the PhysicsTools folder and you see that PatExamples were changed recently with a message test message.

It showed you are checkout done of specific packages and how you are able to save your local changes at your private GitHub account. Git has a lot more feature which help and support you in developing and keeping track of your code. Please visit for more detailed information on branches, merging them, tags, etc.

Git Tutorials and Info


CMSSW releases

To find out which CMSSW releases are available, do:

scram list CMSSW

You'll see a list with names like CMSSW_x_y_z, some with other suffixes. The names point to directories, e.g.,

CMSSW CMSSW_9_4_2 -->  /cvmfs/

For each listed directory, subsystems are under its src directory, i.e., under /cvmfs/ . As an example, let's list the subsystems under this directory:

ls /cvmfs/

Alignment            DQMOffline                  HLTriggerOffline     OnlineDB           RecoLuminosity          SimG4Core
AnalysisAlgos        DQMServices                 HeavyFlavorAnalysis  PerfTools          RecoMET                 SimGeneral
AnalysisDataFormats  DataFormats                 HeavyIonsAnalysis    PhysicsTools       RecoMuon                SimMuon
BigProducts          DetectorDescription         HiggsAnalysis        QCDAnalysis        RecoParticleFlow        SimRomanPot
CalibCalorimetry     DiffractiveForwardAnalysis  IOMC                 README             RecoPixelVertexing      SimTracker
CalibFormats         Documentation               IOPool               RecoBTag           RecoRomanPot            SimTransport
CalibMuon            EgammaAnalysis              IORawData            RecoBTau           RecoTBCalo              TBDataFormats
CalibTracker         ElectroWeakAnalysis         IgTools              RecoCTPPS          RecoTauTag              TauAnalysis
Calibration          EventFilter                 JetMETAnalysis       RecoCaloTools      RecoTracker             TopQuarkAnalysis
CaloOnlineTools      FWCore                      JetMETCorrections    RecoEcal           RecoVZero               TrackPropagation
CommonTools          FastSimDataFormats          L1Trigger            RecoEgamma         RecoVertex              TrackingTools
CondCore             FastSimulation              L1TriggerConfig      RecoHI             SLHCUpgradeSimulations  Utilities
CondFormats          Fireworks                   L1TriggerOffline     RecoJets           SUSYBSMAnalysis         Validation
CondTools            GeneratorInterface          MagneticField        RecoLocalCalo      SimCalorimetry
Configuration        Geometry                    Mixing               RecoLocalFastTime  SimDataFormats
DPGAnalysis          GeometryReaders             MuonAnalysis         RecoLocalMuon      SimFastTiming
DQM                  HLTrigger                   NOTICE               RecoLocalTracker   SimG4CMS

Each subsystem contains several packages, for example

ls /cvmfs/

APEEstimation     CocoaFit         CommonAlignmentAlgorithm        HIPAlignmentAlgorithm        MuonAlignment            SurveyAnalysis
CTPPS             CocoaModel       CommonAlignmentMonitor          LaserAlignment               MuonAlignmentAlgorithms  TrackerAlignment
CocoaApplication  CocoaToDDL       CommonAlignmentParametrization  LaserAlignmentSimulation     OfflineValidation        TwoBodyDecay
CocoaDDLObjects   CocoaUtilities   CommonAlignmentProducer         LaserDQM                     RPData
CocoaDaq          CommonAlignment  Geners                          MillePedeAlignmentAlgorithm  ReferenceTrajectories

with directories such as interface (containing the header files), src (containing the *.cc files), plugins (defining the modules to be used), python (containing the configuration files), doc (containing files needed for reference manual documenation), test (containing test setup) and data (obsolete).

Review status

Reviewer/Editor and Date (copy from screen) Comments
NitishDhingra - 21 Jun 2018 Updated to CMSSW_9_4_2
AndreasPfeiffer - 07 Dec 2015 updated OS version to SLC6 and CMSSW_7_4_15
AndreasPfeiffer - 05 Apr 2011 updated OS version to SLC5
KatiLassilaPerini - 08 Jul 2008 added addpkg
AndreasPfeiffer - 12 Feb 2008 reviewed page, added info on how CVSROOT will change in 2008
LucasTaylor - 27 Nov 2006 reviewed page and made modest changes
KatiLassilaPerini - 18 Oct 2006 changes modules -> subsystems, packages, directories

Responsible: SudhirMalik

1.5 Where to get help

Complete: 4
Detailed Review status


This WorkBook chapter describes many of the help, information and documentation sources available for CERN and CMS users.

There is a very good resource here regarding getting good support from software experts.


Main web pages

For new users, even the main web pages for CERN/CMS can be hard to find. Some useful links are:

User support and Help: Main CMS homepage: CERN IT Computing Service Desk: CMS Reference Manual: CERN main users page: CERN document server (very useful): CMS Computing and Physics Technical Design Reports: CERN Search Page: CERN users office (important for new users): CMS public info: CMS twiki: CERN public page: SWGuide: CMS Conference server (CINCO) :

Email and CMS.HyperNews

For a distributed community such as CMS, email is the primary means of communication.


MMM, (My Mail and More): is the CERN mail service. To access MMM mail, you will need a CERN NICE account (CERN SSO) for accessing Windows computing services, and will need to contact the CMS administration to obtain a MMM account. Most offsite users have their CERN email forwarded to their primary email account at their home institution, but that is NOT always setup by default. You may miss important emails about events/workshops you have registered for as well as grid certificate renewals if you do not ensure your email is not forwarded.

CERN mailing lists

A number of mailing lists exist in CERN to provide a discussion facility for people working on similar projects. The CERN mailing lists are defined in e-groups: To login you'll need a CERN NICE username and password (CERN SSO). Once logged in, you can search for a group and you can show the groups you are on.

Once you are subscribed, you can send an receive emails sent to where groupname is the name of the e-group you are subscribed to. Some of the e-groups archive the mails sent to the group. This feature can be configured by the group owner.


HyperNews is a collection of discussion groups and is set to supercede standard mailing lists as the primary discussion tool in CMS. To set up a HyperNews membership, start in HyperNews allows you to look through articles using a web browser within individual groups, and also to respond to those articles within a web browser. All HyperNews groups also have mailing lists associated with them so that you may also "subscribe" to groups of interest and thereby receive a copy via email of each article submitted. Responses may also be made via email as with a standard mailing list.

CERN HyperNews has evolved from the BaBar HyperNews technology, and provides full archiving of conversations as well as effective search capabilities. At CERN parallel HyperNews systems are run for CMS and ATLAS, though CMS users can only access the CMS branch of CERN HyperNews unless they also hold an ATLAS account.

Getting CMS HyperNews access

Access to the CMS HyperNews forums is restricted to CMS members with AFS passwords (or by special request to the CERN HyperNews Administration: (use this option sparingly). You will have to create a HyperNews membership in order to have access.

To create your own HyperNews access, follow the instructions on the New Membership Page for CMS: These instructions will have you ssh into your lxplus account (using your CMS afs username and password) and create a HyperNews password. Do not choose the same password as you use for normal afs access. From there you can go back to the main CERN HyperNews page and access CMS HyperNews with your new password.

Using CMS HyperNews

Once connected to the main HyperNews page, select "View forums by category" to see what's forums exist already, and to subscribe to any, select "Subscribe to forums". The top menu bar also offers an excellent search engine to search within CMS HyperNews.

All CMS members using central computing tools (CRAB, DBS, CMSWEB...) must subscribe to the CERN Computing Announcements forum where news about services run by CMS at CERN are posted.

General guidelines

  • Avoid cross-posting to several forums
  • Observe usual etiquette and civility to other HyperNews users
  • Try to select the most appropriate forum to post your enquiry/announcement to
  • Do not post attachment (they'll get stripped off before your posting goes out) unless you send your message from the HyperNews web interface and use the "Attach" button to do it - it is better to put your attachment somewhere on the web and provide a URL for interested users
  • Quote only relevant parts of the previous email/s, and include the name of the poster of the quoted text. Remember that users can browse all of the previous postings to the forum via the web interface, so it is unnecessary and wastes space to quote huge portions of a conversation.
  • If the you get overloaded by postings from the HyperNews you can unsubscribe and follow the discussions by reading the recent posting from the link provided in the HyperNews page (
Related HyperNews links

Suggested HyperNews forums for new users to subscribe to:

CMS-wide announcements

The announcements for all CMS physicists are sent to the Physics Announcements Hypernews Forum: Make sure that you are subscribed to this forum.

All CMS members using the Grid must subscribe to the CERN Computing Announcements Hypernews Forum:

CMS Computing and Software User Support

The general User Support page: gives a brief introduction to the CMS Computing and Software User Support and a collection of useful links.

Fireworks Event Display Support

From the main WorkBookFireworks twiki, there is a page with dedicated WorkBookFireworksHowToFix information. Alternately, you can search or email the visualization hypernews. Go to Hypernews on this page to learn more about how to subscribe and access Hypernews.

Contact Online with Savannah

Users can submit questions through the CMSSW Savannah page: You do not need to login to savannah in order to submit questions, but it is recommended as when you login (which requires registration), notifications of the follow-ups will be e-mailed to you. Choose the category corresponding to your question. If you are not logged in in savannah, you will need to type your e-mail address. Choose the release you are using, and specify the severity (you can also leave this field unchanged). (If you are logged in, you see the Status and Assigned to fields which you should leave unchanged.) Type the short summary which describes your problem in the Summary field, and describe your problem in the Original submission field. Remember to specify
  • on which machine you are running
  • what configuration file you are using
  • which data you are trying to access
If needed, you can attach files (output, config files etc) by clicking on the Browse button under Attached files. When completed, submit the question by clicking on the Submit button. Note that if you are not logged in, you may get a warning on the top of the page that your mail is being checked by spam filters.The notification goes to the support staff and to the conveners of the task corresponding to the category chosen. You will get an e-mail on submission with a link to your question in savannah, and you will get an e-mail notification on each update. Do not reply to these mails for further communication, but always follow the given link and write your reply in the Post a comment field. -->

Grid Help at CMS

The Grid Analysis Job Diagnosis Template guides you through steps which will allow you to identify the problems you experience with your grid analysis jobs and instructs how to report the problems.


CERN IT department provides support to CMS related problems with CERN facilities (e.g. lxplus, batch jobs, stageing files), send mail to . Alternatively, you can contact the CERN Service Desk which will direct your question to the appropriate service and provide a ticket with which you can follow your request.


At FNAL, you can contact LPC Computing Support.

Grid Help through GGUS

Grid-based problems can be handled by GGUS (Global Grid User Support): Do not send application (CMSSW, CRAB) problems to GGUS.


Much useful information can be found by browsing through the presentations given at previous meetings, many of which are stored at CERN through the agenda system. It is also often possible for users to attend CERN-based meetings through Vidyo.

Conference/Meeting Agendas

The CERN Indico tool: stores notices of forthcoming meetings, as well as archiving presentations from past meetings. Following the links, you should select "experiments", and follow that link to "CMS". From there are links to CMS-specific meetings (links conferences, workshops, etc are also present on the main agenda page).

Note that the 'CMS meetings' category containing the CMS agendas in indico is now protected. It is only accessible to CMS members (and CMS Emeritus) who are registered in the CMS database and who login indico with their NICE login (CERN SSO) in the ZH group (ZH=CMS group).

Presentations archived on the agenda system can provide a very useful start for learning about a new task or analysis topic.


Vidyo is a tool to enable communication between remote parties, i.e. for people working over IP networks (e.g. through personal laptop computers). This system is widely used for CERN meetings, enabling geographically distributed users to join meetings, see other meeting attendees, and to work collaboratively using chat, desktop sharing, general meeting software, ...

A virtual room is a virtual space where all participants in the meeting can see each other, discuss, and work together - with much the same ease as being together in the same physical room.

To use Vidyo, someone must have booked one of the virtual rooms ahead of the meeting, and told others the name of the room (usually a simple everyday word or linked from an indico page). With your CERN SSO account, you can also invite people to your person meeting room.

More information about 3 main topics concerning Videoconferencing from the IT Audiovisual Service:

  1. CERN videoconference rooms:
  2. How-To organize a videoconference at CERN:
  3. Recommendations for Audio and Video hardware for desktops and laptops to use with EVO and others (available from the CERN stores):

Connect by Vidyo conference

Vidyo is a tool to allow users to make point-to-point calls or multipoint videoconference meetings from their desktop machines, tablets and smartphones, H323/SIP equipped meeting rooms and from traditional phone lines. All CMS members who are registered with lxplus/CERN account should already have a Vidyo account using their CERN SSO. Users are encouraged to look at Vidyo

Dedicated instructions for sub-topics in Vidyo:

  1. Instructions to create a Vidyo room in for Managers
  2. Using Vidyo meeting rooms at CERN for managers
  3. Videoconferencing support in the CERN service portal
  4. Vidyo joining a meeting by phone bridge

Telephone conferences

Telephone conferences at CERN can be booked by sending an e-mail with the following information:

Name of the meeting (you should tell the participants the same): 
 Number of participants: X max.

Tell the participants to call +41 22 767 7000 and ask to join the meeting.

CMS Notes and other Scientific Documents

There are several kinds of CMS Scientific Documents, some publicly available and others internal to CMS. The internal documents are structured in three areas: Analysis Notes, Detector Notes, and Internal Notes. The public documents, besides the Journal Publications and the Theses prepared by CMS students, exist in three flavours: the CMS Notes, the Conference Reports, and the Physics Analysis Summaries. A detailed listing, together with some relevant information to each of the several cases (and useful links), is available in the CMS Scientific Publications web page, which also contains instructions concerning Submitting a document to the CMS approval process. The submission procedure depends on whether the document concerns physics or technical results.

The same page provides other useful information related to CMS Scientific Publications, including direct links to the procedure for the approval of physics analyses, guidelines concerning the style of the CMS physics publications, etc.


The task of the CMS Conference Committee is to promote and to facilitate the presentation of results of CMS to the broad international public. This includes conferences, workshops, symposiums and the like. Presentations at international laboratories are treated as conference talks (as of October 23, 2015, this includes seminars at CERN and the Fermilab "Wine and Cheese" seminar series).

Cms INformation on COnferences (CINCO)

CINCO web pages are provided to CMS members to deal with the handling of conferences and presentations (talks and posters). The list of all CMS conferences is maintained on a central web site. Each conference has a custom-made conference web page that in turn lists presentations and selected speakers. The process of selecting speakers is handled through these web pages by nominating speakers for individual presentations. The web pages provide an archive for past presentations as well as the system to prepare future conferences, examine and approve presentations and select speakers.


All the news regarding CMS conferences are posted at the Conference Announcement forum on Hypernews via e-mail to

Contacting the Conference Committee

The members of the committee can be contacted using the generic e-mail address Feel free to contact any or all of the committee members with any inquiries related to conferences with CMS presentations. Remember to re-edit the e-mail address to remove the Twiki spam protection

Title and Abstract

Any presentation (talk or poster) at a conference has to be first created in CINCO, with title, abstract and appropriate flags for approval by the concerned conveners. It is very important that each presentation has a well prepared abstract. The person entering the presentation into CINCO should describe what shall be presented in an abstract. For abstracts with contents related to POGs and PAGs a list of references is required. They can be added following the Update Bibliography link from the Presentations menu after the presentation has been defined. Abstracts can be prepared in advance by the physics groups or sub-detector committees.


Each presentation in CINCO should list bibliography with references to PAS or other publicly available CMS notes.

Approval of Abstracts

Before abstracts are submitted to the conferences, they must be approved by the relevant convener. The CMS Conference Committee or the prospective speakers should seek the approval of the conveners. Depending on the conference, abstracts are submitted centrally by the CCC, or the selected speaker is asked to submit. In the second case, the speaker will receive instructions from the CCC to do so.

Speaker Selection

Potential speakers may volunteer (self nominate) or be nominated by someone else. Nominations are usually for a specific presentation at a given conference. Follow step-by-step instructions for the collaborators. It is very important to add one or a few sentences of recommendation to the nomination, with good reasons explaining why the nominee is best suited to give the presentation.

Starting in February 2009, Institute Representatives, Group Leaders and in fact anyone in CMS is allowed to identify (or recommend) good speakers for future talks without specifying a particular talk. Detailed instructions on how to provide information to the committee are here.

Step-by-step procedure of arranging a talk

The Conference Committee coordinates the CMS presentations by communicating with the conference organizers and the interested CMS members. The committee is continually improving the policies and practices. The Conference Committee Help pages contain updated step-by-step instructions for the collaborators.

Invited talks

Talks are only considered as “invited talks” if the following facts apply:

  • the invitation is personal
  • the talk has the typical characteristics of an invited talk, i.e. the talk should be an overview or review. The only exception to this rule is talks at national meetings and restricted groups discussing special topics.
When receiving an invitation for a talk please add the talk to CINCO and inform the conference committee without delay. If the talk is eligible for an invited talk you will immediately be acknowledged as the speaker.

See also the guidelines for invited talks:

Student talks at national meetings and schools

The rules for student presentations at national meetings and schools, especially concerning the presentation of unapproved physics results, is defined here:

Presentation file upload

A week before the conference, the draft presentation file shall be uploaded by the speaker to CINCO, for screening by the collaboration and approval. If the Bibliography (see above) is missing, incomplete, or inaccurate, please update it at this time. The appropriate conveners will get automatic mail from CINCO after upload, provided the appropriate category flags are set for the presentation.

Conference Proceedings

Conference proceedings need to be approved by the CMS Publications Committee. To start the approval process the authors need to upload the final version of the proceedings pdf file through a dedicated web page in CINCO.

  1. Navigate to the CINCO web page corresponding to your talk or poster
  2. Make sure that the title and abstract match exactly the title and abstract of the proceedings
  3. Select Submit Conference Proceedings option from the Presentations menu.
  4. Make sure that all the options are properly adjusted and submit the document to the Icms system.
After you submit the pdf file it will be reviewed by a referee. Expect about 2 weeks for the review process to be completed if the paper contains new material from CMS only and about 3 weeks if it also contains new material from another experiment, e.g. ATLAS. The updates to the document need to be handled through the Icms system ( Collaboration tab, bottom left corner, iCMS publications link).

Only after you receive a go-ahead from the Publications committee you can submit the proceedings to the conference organizers. Make sure you start the approval process early enough so that you do not miss the deadline for submission to the conference organizers.

When writing conference proceedings, please adhere to the following guidelines:

  1. A conference report is published under the responsibility of the author and not of CMS as a whole, so the refereeing process is lighter than for a standard CMS paper.
  2. A CMS subeditor will be assigned to review the paper. When approved by the subeditor, the PubCom chair (or deputy chair) performs a few final checks and, in the case of joint ATLAS-CMS conference reports, submits the draft to the ATLAS PubCom for approval. Any further communication with ATLAS is handled by the PubCom chair (or deputy chair).
  3. To facilitate the review process, the draft should have line numbers. These need to be removed when producing the final version to be published on CDS.
  4. The paper should be signed as 'XY on behalf of the CMS Collaboration' (or the ATLAS and CMS Collaborations, in that order).
  5. The report should include a reference to the CMS detector paper, "CMS Collaboration, JINST 3 S08004 (2008)", and for an ATLAS-CMS report also to the ATLAS detector paper, "ATLAS Collaboration, JINST 3 S08003 (2008)".
  6. Text, figures, and tables should be consistent with approved CMS results and cite the correct reference. Each figure caption should explicitly cite the document from which the figure is taken.
  7. Conference reports are a historical snapshot of results as they were presented at the time of the conference. Thus the plots and results cited in the conference report should reflect what was actually shown at the conference. If, however, more recent results become available before the report is published, it is recommended to mention this fact briefly in the text or a footnote, with a proper reference to the new results.
  8. After final sign-off by the PubCom chair (or deputy chair), the conference report is assigned a number and is published on CDS. Only then can it be submitted to the conference organizers.

If you have any questions please contact the chair and deputy of the Publications committee by sending an email message to

Please notice: Students' talks at national conferences sometimes include material which has not yet been approved by CMS. It is not allowed to include such material in the proceedings.

There is more information about the CMS Publications Committee at Publications

Conference Committee Internal Procedures

The Conference Committee is working on optimizing its internal procedures. We are in process of documenting on how we do things.



The CERN website can be rather difficult to navigate through - though if you know the keywords you are interested in, and can find it, the CERN search engine is useful:

Links to the search options are all on the CERN Users pages, though they can be tricky to find.

You can search the CERN Document Server for papers, photos, meetings, presentations, etc, on:

And the people database to find information such as the phone number, building number or email address of a colleague.

To find where a particular building is in CERN, use the building search:

Analysis Documentation

The CMSSW software documentation consists of three main components:

  • the WorkBook which is this document
  • the CMSSW Software Guide (described below)
  • the CMSSW Reference Manual (described below)

The CMS Offline Software Guide

The CMS Offline Guide: contains a more detailed description of the CMS software, detailing the use of the various software packages and containing instructions to carry out tasks, e.g. physics analyses, which are beyond the scope of the WorkBook. The SWGuide is rapidly evolving to be the online storehouse for all offline software documentation for CMS.

Reference Manual

The CMSSW Reference Manual: provides an introduction to different domains (data, functional and detector views) and should contain a brief description of contents and purpose of each package.

The Reference Manual is generated using Doxygen: which is a documentation system for programming languages including C++ (the language of choice for CMS programme), Java, Python among others. It is an easy-to-use tool which can be used to generate online documentation (html), as well as a text manual (latex source), from a set of documented source files.

For a set of interrelated packages with various classes, the documentation includes dependence diagrams showing inter-class relationships, and provides hyperlinked listings of functions, data members, class headers, etc. Since the documentation is generated directly from the source files, it is easy to keep the documentation up to date - the only caveat being the requirement to provide useful documentation in the code!

While generally Doxygen simply documents the source code and illuminates the various relationships within the code, it can be used to generate a reference manual which complements, but does not replace documentation like the CMS WorkBook which contains introductory material and step-by-step tutorials for new users.

CVS Web Browser

The CVS Web Browser allows you to browse the code (see You can choose a specifc CMSSW version and tag from a pull-down menu from the bottom of the page on any page containing link to files (and not just directories). If you do not select anything, the most recent "head" version is shown.

CMSSW Software Cross-Reference (LXR)

The CMSSW Software Cross-Reference ( is a cross referenced display of the CMS source code. With the LXR tool (LXR stands for "Linux Cross Reference") it is possible to search through the entire CMS source text; or to search for files whose name matches a pattern; or to search for the definitions of particular functions, variables etc.

Sample Use Case

Let's learn a little about the code provided for finding isolated tau tags.

If you want to select events with an identified isolated (i.e. not in a particle jet) tau lepton tag, you need to find the classes and functions which have been provided for you in CMSSW.

To find the code in the CMSSW CVS repository, go to, and use the search facility to find IsolatedTauTag. From the list of results, click on the header file /CMSSW/src/DataFormats/BTauReco/interface/IsolatedTauTagInfo.h to find out what its private data members are:

001 #ifndef DataFormats_BTauReco_IsolatedTauTagInfo_h
002 #define DataFormats_BTauReco_IsolatedTauTagInfo_h
003 //
004 // \class IsolatedTauTagInfo
005 // \short Extended object for the Tau Isolation algorithm.
006 // contains the result and the methods used in the ConeIsolation Algorithm,
007 // to create the object to be made persistent on RECO
008 //
009 // \author: Simone Gennai, based on ORCA class by S. Gennai and F. Moortgat
010 //
012 #include "DataFormats/BTauReco/interface/RefMacros.h"
013 #include "DataFormats/Math/interface/Vector3D.h"
014 #include "DataFormats/BTauReco/interface/JTATagInfo.h"
015 #include "DataFormats/JetReco/interface/JetTracksAssociation.h"
017 namespace reco { 
019   class IsolatedTauTagInfo : public JTATagInfo {
061   private:
062     TrackRefVector selectedTracks_;
063   };
065   DECLARE_EDM_REFS( IsolatedTauTagInfo )
067 }
069 #endif // DataFormats_BTauReco_IsolatedTauTagInfo_h

From line 19 we see that IsolatedTauTagInfo inherits from the class JTATagInfo. Click on JTATagInfo, and select its header file to learn, among other things, that JTA stands for Jet Tracks Association.

Further information

Other Documents

There are many sources of documentation about for CMS users. The CERN Document Server: enables a search through much of the printed and online CERN media. Further information can be obtained from the sources including General Offline home page:

CERN/CMS Images and Plots

There are over 10,000 images of CERN and its associated experiments on the CERN photo server (see link below). For talks and presentations, a more specialised selection of photos is provided (see link below).

CERN Press Office Multimedia Gallery

Figures from CMS Physics Analysis summaries can be found in a CERN Document server (CDS) collection in Similar collection for all CMS journal publications and their figures is being prepared (September 2009).

CMS plots and images from the Technical Design Report (TDR) times can be found in -- under each TDR there is a "Figure gallery".

Other useful help links

Review status

Reviewer/Editor and Date (copy from screen) Comments
StefanoBelforte - 2020-11-26 update HyperNews info
MargueriteTonjes - 4 April 2018 overhaul, removing EVO links
XuanChen - 16 Jul 2014 replaced the link of “How-To organize a videoconference at CERN”
AndriusJuodagalvis - 17-Sep-2010 A note on EVO CMS community
JennyWilliams - 09 Oct 2007 redid LXR example to use current code
JennyWilliams - 26 Sep 2007 updated info on SWGuide
KatiLassilaPerini - 26 Jun 2007 Updates on EVO
CMSUserSupport - 20 Nov 2006 (Kati Lassila-Perini) Updated the User Support part)

I went through chapter 1 section 4 .(email from morelos to Kati).

The information is relevant and clear.

This section has several links out of date, they require little direct work.

In several email addresses, it will help to add the warning "(remove SPAMNOT)".

I would suggest to update the link at " here "

I would suggest to update the link at " CERN IT Computing Helpdesk "

I would suggest to update the link at "Offline Software Guide "

I would suggest to update the link at " LPC "

I would suggest to update the link at ""

I would suggest to update the link at ""

I would suggest to update the link at "Information on CERN sites "

I would suggest to update the link at "CERN Press Office Multimedia Gallery"

I would suggest to update the link at "CERN Users Office FAQ"

Updated the straightforward links that A.Morelos suggested.

Responsible: SudhirMalik
Last reviewed by: KatiLassilaPerini - 27 Jan 2011

1.6 Information for Newcomers

Detailed Review status



Please visit also the following links for more complete information:

The CERN facility spans two sites; Meyrin in Switzerland and Prévessin in France. The CMS detector is located in France, Cessy (Point 5), which is about 15 km from the CERN Meyrin site 'See map'. The facilities and offices that most CMS members will use when visiting CERN are all in the Meyrin (CH) site.

Procedure for obtaining invitation letter for visas for Switzerland and France

In accordance with the Status Agreement with CERN, Switzerland and France facilitate the entry of members of the Organization’s personnel onto their territories. Where relevant, detailed procedures for obtaining visas apply. Please see: * Visa Requirement and Procedure for Switzerland and France

More information by nationality concerning the visa requirements can be found at Swiss State Secretariat for Migration SEM

Invitation letters request:

Please go to new invitation website to fill in the invitation request. The request will be handled by the CMS Secretariat as soon as possible and the letter (and the relevant documents were applicable) will be sent back to you. On the main page, please read the instructions and select the invitation letter you need from the menu on the right. Please note that the website works only with an active CERN account. If you have a CERN account but you still cannot access the site, please contact the CMS secretariat. If you don't have a CERN account, please register your account as CERN Lightweight account following the instructions on the CERN Account Management main page and, once registered, send a confirmation to the CMS secretariat.

Please contact the local consulate/embassy about 6-8 weeks before (but minimum 3 weeks) your projected travel date, especially in countries where appointments are required for the visa application. Although early applications are encouraged, they should not be made more than 3 months in advance. Original invitations aren't always requested by the consulates, that depends on the local authorities so you need to check that. You also need to make sure that you have a valid health insurance with 'rapatriement' that covers your whole stay.

IMPORTANT to know: You cannot apply to both Swiss and French visas (as both are Schengen) but you must choose depending on which country you are planning to live in.

Not sure where you would like to live? Especially for a long term visa, we encourage you to apply for the French visa D if you have at least 3-4 weeks time ahead and are not fully sure if you will install in France or Switzerland. The Users Office can apply for a Swiss "Carte de legitimation" for the users having a French visa D with the intention of settling in France, but who are temporarily staying at the CERN Hostel in Switzerland. One can also choose to move to Switzerland without too much paperwork.

Those who come to CERN with a Swiss visa D, and would then like to live in France, need to apply for a French visa D from the French consulate in Geneva BUT only after the "Carte de legitimation" is delivered. It is obligatory to stay in Switzerland during that time (at least three months) before one can move to France. To apply for the visa in Geneva, note that also a Swiss local address is required (CERN hostel is not accepted).

Please take note that your Team Leader has to approve your request for the invitation.

CERN associated personnel (users) is allowed up to 3 months' grace at the end of their functions to allow for removal and going back to home countries. The "Carte de legitimation" can be mailed back to the Users Office after home country has been reached.

Short Term Visa

Given that the Organization is located on the border between France and Switzerland, we strongly recommend that you contact the relevant consulates for information on the entry conditions applicable to you in these two countries, specifying the duration and nature of your work at CERN. Where appropriate, you are invited to take the necessary steps to obtain the requisite documents, in particular a visa for entry to the Schengen member countries:

  • either by going to the Swiss Consulate competent for your usual place of residence, taking the CERN invitation letter with you, explaining that you will become a member of the CERN personnel and that as such you will be entitled to freedom of access to, and residence on, Swiss territory under Article 12 of the Status Agreement between CERN and Switzerland dated 11 June 1955;

  • or by going to the French Consulate competent for your usual place of residence as soon as you receive the CERN invitation, presenting the convention d'accueil and explaining that you will become a member of the CERN personnel and that as such you will be entitled to freedom of access to, and residence on, French territory (without visa charges and without delay) under Article XI § 2 of the Status Agreement between CERN and France dated 13 September 1965, as revised on 16 June 1972. It is important that you sign this convention yourself before presenting it to any authorities.

Data needed (as in passport) for the short term (less than 3 months stay) visa request:

  1. Family name(s):
  2. First name(s):
  3. Civil Status (Ms/Mrs/Mr):
  4. Date of birth:
  5. Place of birth:
  6. Nationality:
  7. Complete current address of residence:
  8. Telephone:
  9. Email:
  10. Academic title or status: (undergraduate, graduate, master, PhD, etc):
  11. Employing institute or University:
  12. Address of the institute/univ:
  13. Foreseeable start date of the stay:
  14. Foreseeable end date of the stay:
  15. Date of last entry into Schengen Area (if applicable):
  16. Number of foreseeable visits during one year:
  17. Name of the requesting person (if applicable):
  18. University and Department of the requesting person:

IMPORTANT Everybody coming to work at CERN with a Schengen visa issued by the Swiss authorities for any period of time less than 3 months and needing to go to France for any reasons are requested to have an official CONVENTION D'ACCUEIL document that they must keep with them together with the passport at all times and show at the Users Office when registering.

This document is prepared at CERN, signed by the person coming to CERN then sent for approval to the Sub-Prefecture in Gex, France and then returned to CERN.

The Convention d'accueil covers normally only the duration of the stay in question. A new one must be requested for every new stay. However, for the persons coming regularly to CERN (and who are registered at the users office for less than 51%), it is proposed to issue it for a period of 2 years if the stay does not exceed 90 days at one time.

In most cases you can collect the Convention from the Secretariat.

back to top

Long Term Visa

Given that the Organization is located on the border between France and Switzerland, we strongly recommend that you contact the relevant consulates for information on the entry conditions applicable to you in these two countries, specifying the duration and nature of your work at CERN. Where appropriate, you are invited to take the necessary steps to obtain the required documents, in particular multiple-entry long-stay visas:

  • a Swiss D+C type visa if you are establishing your place of residence in Switzerland, or
  • a French D type visa if you are establishing your place of residence in France or if you have not yet decided where to establish your future place of residence.

For Switzerland: you must go to the Swiss Consulate competent for your usual place of residence, taking the invitation letter with you, and request a visa bearing the words “prise de fonctions au CERN”, explaining that you will become a member of the CERN personnel and that as such you will be entitled to a legitimation card issued by the Swiss Federal Department of Foreign Affairs and to freedom of access to, and residence on, Swiss territory under Article 12 of the Status Agreement between CERN and Switzerland dated 11 June 1955.

For France: you must go to the French Consulate competent for your usual place of residence and request a visa bearing the words “carte PRO-MAE à solliciter dès l’arrivée”, making reference to CERN’s Note Verbale to the French Ministry of Foreign and European Affairs and to the agreement that the Ministry has addressed to the above-mentioned Consulate in your favour, and specifying that you are entitled to freedom of access to, and residence on, French territory (without visa charges and without delay) under Article XI § 2 of the Status Agreement between CERN and France dated 13 September 1965 as revised on 16 June 1972.

As mentioned before, if you get the French long-term visa D, you do not need to have the Swiss visa D as you will receive the Swiss legitimation card at CERN. However, the Swiss visa D is not enough to able one to live in France.

Data needed (as in passport) for the long term (more than 3 months stay) visa requests:

  1. Family name(s):
  2. First name(s):
  3. Civil Status (Ms/Mrs/Mr):
  4. Date of birth:
  5. Place of birth:
  6. Passport number:
  7. Passport issue date:
  8. Place of issue of passport:
  9. Passport validity:
  10. Nationality:
  11. Complete current address of residence:
  12. Telephone:
  13. Email:
  14. Academic title or status: (undergraduate, graduate, master, PhD, etc):
  15. Employing institute or University:
  16. Address of institute/univ:
  17. Foreseeable start date of the stay:
  18. Foreseeable end date of the stay:
  19. Foreseeable place of residence (France/Switzerland):
  20. Date of last entry into Schengen Area (if applicable):
  21. Will you be accompanied by your family:
  22. Name of the requesting person:
  23. University and Department of the requesting person:

Please note that it is important that you provide the same information for your spouse and/or family accompanying you. If you are coming with your spouse, CERN will require a marriage certificate or civil partnership to prove your union. For children CERN will require a birth certificate.

Request a long term visa here

Useful information can be obtained from the Swiss and French diplomatic representations abroad, as well as from the following Web pages:

back to top

Arriving at Geneva Airport (Cointrin) or Geneva Train Station (Cornavin)


A taxi to CERN Reception, building 33 from the airport will cost approx. 35 Swiss francs, from the railway station approx. 70 Swiss francs. The journey takes about 10 minutes from the airport and 20 minutes from the train station.

Public Transport from the Airport and Train Station

On arrival by air, take a free ticket from the ticket machine (baggage claim area). The “Unireso” ticket, issued free of charge by Geneva International Airport, enables you to use public transport in Geneva public transport in Geneva for 80 minutes. This ticket is only valid with your flight ticket to prove that you have arrived on that day.

Otherwise you will need 3 CHF (or equivalent in EUR) to buy a bus ticket from the ticket machine at the bus stop.

See: How to get to CERN and Geneva transport website TPG

There is a regular shuttle service between CERN (building 500) and the Geneva Airport every hour from 08:00 to 19:00, from Mondays to Fridays (except public holidays and CERN end of year closure). Shuttle bus No 4

Note that continuing roadwork at the airport requires frequent change of the shuttle stop location. Please consult the web site before your arrival.

To get to CERN from the Train station take the tram number 18 (marked with terminus "CERN" in front) to CERN directly.

Arriving at CERN

CERN Reception is open from 8.00 a.m. to 5.45 p.m. (Monday – Friday) and from 8.30 a.m. to 5.15 p.m. (Saturday).

If you arrive during working hours, your first stop should be the CERN Reception in Building 33. . You will receive a temporary visitor pass from the reception. They will indicate to you where to go e.g. to the CMS Secretariat in bldg 40/5-B01.

back to top


Be fairly quick with a hostel reservation as they are often very full, but they only take reservations two months in advance. It is a bit cheaper to live on the French side of the boarder.

You can consult the CERN Housing Service website which includes information relating to the CERN hostel booking rules, special negotiated rates for hotels in the local area, rental offers from the local private sector, etc. Or the CERN Housing Service team can be contacted directly in case you have any queries (reception in Building 39, tel. 74481).

The easiest and quickest way to reserve rooms at CERN is via the web booking tool . Please note that any reservation canceled less than 48 hours in advance will incur a one-night payment penalty - if you change plans please inform the hostel as soon as possible so that the room can be re-allocated.

Please note that some websites (e.g. CERN market) are only accessible to CERN users. You can therefore create a lightweight account prior to your arrival: External Account

St. Genis Hostel

Address: Foyer Résidence Schumann, 340 rue de l’Europe F-01630 Saint Genis Pouilly, France Tel: 00 33 (0) 450 42 13 66

The reception desk at the St. Genis hostel is open from 16h00 to 19h00 for check-in, but you can leave luggage at the reception desk from 8h00 to 12h00. You have Wi-Fi connection in the hostel.

Transport to the Hostel from CERN

At CERN you can get a shuttle bus to the hostel during the opening hours of CERN. Outside opening hours you can take the Y bus or ask for a taxi from the Guard at gate B.

Equipment in kitchen

The kitchens are equipped with a fridge, hot plate, hot and cold water. There is no equipment for cooking like pots, pans, plates, cups, knives, spoons, etc. The supermarket is close by for buying all kinds of food and essential cooking equipment.

Meyrin Hostel

Address: CERN Meyrin site, Building no. 39, Meyrin, Switzerland Tel. 00 41 (0) 22 767 44 81

The reception desk is open from 7h30 to 00h30. You have Wi-Fi connection in the hostel.

Late arrival If you arrive after opening hours, go to the Entrance gate B and announce yourself to the Guard. He will give you your room key and show you where the hostel is, just a short walk on foot from entrance B.

Accommodation Outside CERN

There are many hostels in or around Geneva center which will take people for anything from a night to several years. However there are always long waiting lists and you must almost always reserve a room long in advance.


Geneva University

Foyer George Willimas

Hostels with Dorm-Rooms

Home Saint Pierre

City Hostel Geneva


Reasonably Cheap Hotels

Geneva hotels negotiated prices for CERN Users

Hotels in the Area

Private accomodation

Private market accomodation

Housing in Saint Genis


In France: Leman Location - 25 av. Voltaire, 01210 Ferney Voltaire email: - this is a very small company but considerably cheaper than any of the big companies.

back to top


In accordance with the CERN Staff Rules and Regulations, your social insurance cover, as well as that of any accompanying family members, is the responsibility of your home institute or, failing that, is your own responsibility. It must comprise health insurance covering the financial consequences of illness and accidents at a level adequate for both France and Switzerland. In particular, kindly note that: − at the time of completing the CERN arrival formalities at the latest, you will be required to supply proof of health insurance cover for yourself and any accompanying family members;

For updated information, please refer to Users Office -Health Insurance Information

Other insurances but be careful what they cover: Golden Care and Swiss Care

back to top

Registering at CERN

Before coming to CERN, you must make sure you have all the required documents. You should work your way through the correct registration form. You should get the registration form signed by the authorized person before you come to CERN, this will make the procedure much faster. Please have a look at the Users Office Homepage. These pages contain most of the information you need for coming to CERN.

Find out who your Team Leader is since you will need his/her signature on the Users Office registration form. Team Leader can also pre-register a new user: Pre-Registration Tool.

Note that you will need a copy of the invitation letter(s), your passport, proof of your medical insurance including death and disability (an insurance card is sufficient), and a Home institution declaration, to be completed by an authorized representative of the candidate’s home institution for the purpose of issuing the candidate a contract of association with CERN. As of now, only a Home institution declaration signed by a person from the administration is acceptable, not one signed by the Team Leader (unless a letter from the administration has been sent to the Users’ Office indicating that the Team Leader has the right to sign such attestations on behalf of the employer).

On your first full working day, you’ll need to visit the Users’ Office. It is located near the restaurant, bank, and the post office in building 61. Take all the documentation mentioned above. You will then be asked to go to building 55 to collect your CERN access card.

Registering with CMS

Once your CERN registration is done, please pass by the CMS Secretariat in bldg 40-5-B01 to register in the CMS database. To be officially registered in the CMS people database, please send an email to the CMS secretariat.

After the form has been submitted, an email is sent to your Institute Representative (Team Leader) for approval.

Upon arrival, please have a look at the Twikipages of Welcome to CMS

back to top

Creation of Computer Account

Before you get a Computer Account on the IT-CMS server, you must be registered both in the CERN Database and as a collaborator in the CMS database. Then follow the instructions given in section Getting a Computing Account.

Laptop Registration

The NICE account is needed (and activate at least one day earlier) for the registration of a laptop. Open the wireless, search for the “CERN” network and follow the instructions.

In case you need Ethernet, it has to be registered separately as well as the wall plug. For details, see: Network.

CMS Safety

Please read carefully the Safety at CMS web pages for information e.g. about Safety Training and Awareness, Internal Accident report and the FAQ, which contains lot of useful information on safety but also about how to organize a private visit to CMS or how to become a CMS guide.


Please read carefully the Dosimetry Service web pages for information about getting a dosimeter (and note the medical certificate requirements that exist in some cases). You should wear a dosimeter when at CERN unless you are working only in offices. It is compulsory if you are in a radiation controlled area, e.g. a radioactive source in a laboratory. In view of the significant increase in the number of CERN users, the CERN Medical Service is unfortunately no longer able to deliver these certificates. They kindly ask you to provide a new medical certificate delivered by a doctor designated by your home institute or, if your home institute agrees, a local doctor. A list of local doctors able to provide such a certificate is available on the Medical Service website Medical Service.

back to top

Subsistence allowance and other payments

If you are entitled to receive payments from CERN during your stay at CERN, please make sure that your bank details are properly registered by filling out this EDH form, once you have a CERN Computing Account.

More information can be found in the CERN Admin guide:

Registration of bank details

Payment and reimbursement forms

As CERN payments are in Swiss Francs, it is important to make sure your bank will be able to receive this currency.

For payments initiated by the CMS collaboration, please contact Ani Yaneva (in 40-5-B05) or Kirsti Aspola (in 40-5-A24).

back to top

Other Useful Information

Cost of living

It is important to compare the cost of living in Switzerland and France as the prices of accommodation, food, leisure activities, etc. do vary from one to the other.

back to top

Bringing pets

We keep pets out of interest in the animals or as household companions. They accompany us and are not intended for sale. Special import regulations apply for dogs, cats, ferrets and birds as pets. Pets are animals of the species, which are kept out of interest in the animals or as household companions. They accompany their owners or persons acting on behalf of the owners. Pets are not to be sold or passed on to new owners. See the links below:

Bringing pets to Switzerland

Federal veterinary office FVO

Bringing pets to Switzerland

Dogs, cats, ferrets from the EU;

Dogs, cats, ferrets from third countries;

Special case birds. Pet birds from third countries;

Restrictions on import: Import bans / Temporary restrictions / Special conditions

* The import requirements arising from the laws on conservation on species apply for protected or non-domesticated species even if those are deemed pets. See link "Wild Fauna and Flora / CITES".

Bringing pets to France

Conditions for importation into France of pets, from countries not members of the European Union

Animals may carry serious diseases such as rabies or bird flu. Customs contributes to the protection of national territories and community health monitoring including documents and support of these animals.

European legislation regulates the movements of domestic carnivores (cats, dogs and ferrets) to limit the risk of introducing animal diseases, including rabies.

You want to bring to France a cat, dog or ferret

More information is available on the website of the Ministry of Food, Agriculture and Fisheries.

back to top


To make local calls, you can purchase cheap SIM cards at the general store in the main building for 20 CHF. You get a SIM card with 20 CHF credit and cheap local calls and texts and good rates for texting overseas. The drawback is that all the instructions are either in French, Italian or German! For international calls you should investigate the calling cards, which are available in many shops.

CERN Phone and Email Directory


A universal plug adaptor will be useful, as Swiss and French electric plugs are different. Warning: Electricity at Europe is distributed as: Voltage 220 Volts and 50Hz (USA 120 Volts and 60Hz). Before connecting anything to electricity, please verify that your device works under European Voltage & Frequency, or get a proper transformer

Language and Currency

CERN is a bilingual international organization (French/English).

In Switzerland, Swiss Francs (CHF) are the local currency, while in France the Euro is used, and there are few places that will take either currency. The automatic teller machines in the main building on the Meyrin site provide cash in either currency (though for foreign cards they will provide only Swiss Francs).

Should you need to open a bank account in Switzerland, you can open an account with the UBS bank which has a branch in the main building (building 500), but you need to stay at CERN more than 6 months. You can also open one at the Post Office also located in the main building once you have obtain a local address either in Switzerland or in France.

back to top

Getting Around

The tram 18 takes you to the center of Geneva. The ticket costs 3 CHF and it can be bought from a ticket machine at each bus stop. There a two types of machines and the new ones give change. You can also buy 20, 30 or 50 CHF bus cards ("cartabonus") at the news stand in the main building but only the old ticket machines accept these cards.

A recommended point to get off for your first trip into town is the train station, Gare Cornavin. This puts you essentially in the centre of town, and it’s very easy to find the tram back to CERN.

Note that you can also borrow bikes from CERN for free during your stay. A refundable deposit of 450 CHF is required (can be backed up by Team Account) and lights and a lock are provided, as well as servicing for punctures and other problems.

Geneva Public Transport (TPG)

back to top


There are plenty of cinemas with English- and French-language viewings of films in Geneva. You should check in advance to determine the schedules and languages of the presentations.

back to top

CERN Student Activities

CERN’s student activities for all young people coming to CERN for any length of time may be found at LPCC page.

Other Useful Links

CERN Welcome Centre

CERN Buildings and Sites

CERN Guide for Newcomers

CERN Health Insurance Scheme-CHIS

CERN Users Office FAQ

Shuttle Service

USCMS Guide to Coming to and Living at CERN

CERN Clubs

CERN Market (vehicles, housing, furniture, etc.

Swiss Info

Anglo Info

back to top

Review status

Reviewer/Editor and Date (copy from screen) Comments
JosephineEmilieBengtsson - 2021-03-02 updated outdated links, formatting, and housing info
KirstiAspola - 2019-10-15 updated how to getto CERN info
KirstiAspola - 2019-04-12 added link to CMS Welcome Twiki page to registering with CMS
AniYaneva - 2019-03-29 updated the Subsistence allowance and other payments information and links
KirstiAspola - 2018-06-13 updated the visa information links
YaseminYazgan - 2018-01-24 added US CMS invitation website and modified wording to make sure all US CMS collaborators can contact me
KirstiAspola - 2017-02-10 updated and added some links
KirstiAspola - 05-Nov-2015 added new invitation website information, general editing
KirstiAspola - 26-Jan-2015 updated insurance info
KirstiAspola - 08-Jan-2015 updated insurance info
KirstiAspola - 17 Nov 2014 updated insurance info for frontalier workers who are family members of a CHIS main member
KirstiAspola - 06 Nov 2014 updated insurance and dosimeter info
KirstiAspola - 09 Sep 2014 updated and added some Useful information links, modified insurance info
KirstiAspola - 01 Sep 2014 updated CERN and CMS registration information
XuanChen - 16 Jul 2014 replaced the links of "hostel reservation”, “CERN Housing Service” and “Summer Students Information Page”
KirstiAspola - 02-Jul-2013 added info about invitations and added lightweight account to accommodation section
KirstiAspola - 18-Jun-2013 added info on CMS Safety
AnastasiaDolya - 25-April-2013 updated Tram info, Registration at CERN - home declaration
KirstiAspola - 07-May-2012 added Civil Status for information needed for visas
KirstiAspola - 19-Jan-2012 general updating, P5 map, insurance, invitations
KirstiAspola - 08-Jul-2011 EPLANET, updated links
KirstiAspola - 23-Jun-2011 minor general editing
PolinaMorozova - 26-Oct-2010 general editing
KatiLassilaPerini - 25-Nov-2009 updated links
KatiLassilaPerini - 08 Dec 2008 updated users office links
KatiLassilaPerini - 24 Jan 2008 minor edits
KatiLassilaPerini - 28 Nov 2006 Implemented comments from Marie-Claude
JennyWilliams - 07 Oct 2007 General editing, and added comments about cell phones and bikes

Responsible: KirstiAspola

Please send comments to Kirsti Aspola

Edit | Attach | Watch | Print version | History: r11 < r10 < r9 < r8 < r7 | Backlinks | Raw View | WYSIWYG | More topic actions
Topic revision: r11 - 2010-01-18 - KatiLassilaPerini



    • Cern Search Icon Cern Search
    • TWiki Search Icon TWiki Search
    • Google Search Icon Google Search

    CMSPublic All webs login

This site is powered by the TWiki collaboration platform Powered by PerlCopyright &© 2008-2021 by the contributing authors. All material on this collaboration platform is the property of the contributing authors.
or Ideas, requests, problems regarding TWiki? use Discourse or Send feedback