discussions with fact checkers and others, towards improved documentation, vocabulary and
markup patterns for fact checking videos and images.

There's a draft at the link below from Bill and Joel Luther, which builds
on prior work by the Washington Post. Comments are probably best made
directly in the document (SEOs, please *don't* ask SEO questions there!). The
document includes links to the earlier work mentioned, and to a spreadsheet that
tries to apply the proposal to some real world examples. Please take a look.