Discussion about CF Metadata takes place on GitHub in three forums, using GitHub issues.
For proposing standard names, asking questions or having discussions about the interpretation and use of the CF conventions, and initial suggestions for proposals to change or extend the CF conventions.
There is also a separate website detailing the status of current proposals for new standard names that have been initiated on the general discussion forum.
For proposing enhancements and reporting defects in the CF conventions, that may or may not have started as conversations on the general discussion forum.
For discussing, proposing changes and reporting defects in the CF website, and for discussion of CF governance.
No registration with CF is required to contribute; all that is needed is a freely available GitHub account.
Before the CF community migrated to GitHub, general and standard-name discussion took place on the cf-metadata mailing list, and enhancements to the conventions were proposed on the CF Metadata Trac site.