When a new ONAP project is proposed the initial list of Committers is provided as part of the Project Proposal Template which is presented to the TSC for approval.   The specific wiki version of the Proposal at the time the Project is approved by the TSC defines the actual list of Committers approved for that project. 

However adding a new Committer or removing a Committer once the Project is approved is governed by Section 3.2.2 of the ONAP Technical Community Document

The ONAP Technical Community Document has the official language and specific details that must be adhered to. What is listed here is simply a process overview and not authoritative:

Adding a Committer

Removing a Committer: