In consultation with Legal, we add verbiage (a) instructing users to provide a conflict of interest disclosure on their user page if appropriate, and (b) asking users to refrain from providing labels for edits where the nature of the edit might pose a potential conflict of interest (this is probably rare, but noteworthy).
Are there any general policies that we can link to? If not, we'll need to have them created. For the UI, we can only really afford a sentence or with links out to documentation. Documentation will need to be multilingual.