McM is a webpage used for CERN CMS Monte Carlo Request Management. It is documented at:

It provides the exact commands used to generate official MC samples. To get the commands:

1. Query CMS DAS to get the McM ‘prepid’.
• e.g. dataset dataset=/TTJets_TuneCUETP8M1_13TeV-amcatnloFXFX-pythia8/RunIISpring16DR80-PUSpring16RAWAODSIM_80X_mcRun2_asymptotic_2016_v3-v2/RAWAODSIM gives McM prepid: TOP-RunIISpring16DR80-00030
2. Edit this URL https://cms-pdmv.cern.ch/mcm/public/restapi/requests?prepid=PREPID by replacing PREPID with the McM prepid.

When the DAS web interface is not working, one can also do the search from the command line

• e.g. das_client.py --query="mcm dataset=/TTJets_TuneCUETP8M1_13TeV-amcatnloFXFX-pythia8/RunIISpring16DR80-PUSpring16RAWAODSIM_80X_mcRun2_asymptotic_2016_v3-v2/RAWAODSIM"

A quicker way is simply editing the URL:

There is also a list of all the official campaigns: