Is there a regulation that describes in detail what content must be in a CV? Conversely, is there a regulation that identifies content that should not be included? A CV should demonstrate qualifications and experience. Other than this, I’m not aware of other specific regulatory guidance. Any “restrictions” that I’ve seen (eg a 1-page CV) have been sponsor requirements.
Inclusion of other sponsors on a CV may be a confidentiality issue for those sponsors but I don’t think this is a regulatory issue (perhaps a legal one if they’re under a confidentiality agreement!).