Facebook: FTC Sponsored Content Disclosures - Do's & Don'ts – Later Influence Help Center

Disclosure Do’s

For all social media disclosures, include clear and unambiguous language, using the words or hashtag “sponsored,” “ad,” or “paid” in addition to tagging the sponsoring brand.
For in-feed posts, place disclosures in the first three lines of the description above the “see more” button.
For Facebook Stories, #ad, #sponsored or #paid followed by the brand needs to be superimposed on the first photo in the series. Sequential Stories only require disclosure at the beginning of a series.
For videos in feed, disclosures must be superimposed and verbally disclosed within the first 30 seconds. Superimposed disclosures must stay on-screen for a minimum of ten seconds.
When using the built-in Branded Collabs Manager, manual disclosures are still required.

Use ambiguous language like #sp, #collab, #partner, any branded hashtags or simply “thank” the company for the product/service/compensation.
Hide the written disclosure at the bottom of the description.
Simply tag the brand without mentioning the nature of the partnership.
Rely on built-in, Branded Content tools only.