AO certificate for U.S. movies?

I notice that the movie Enter the Void (2009) - IMDb lists a certificate of "AO (new rating)". Beyond the Valley of the Dolls (1970) - IMDb shows "AO (suggestion)".    Velma (TV Series 2023– ) - IMDb  shows "AO (DLSV, suggestion, new rating, Crude Humor)".

As far as I know, AO only applies to video games.  Does anyone know why this would be applied to a film?  There are 293 films with this certificate  US-AO (Sorted by Popularity Ascending) - IMDb.  It looks like someone has gone to a lot of trouble to insert their opinion into the certificates for unrated, NC-17 rated, and TV-MA rated films.  If so, I recommend that staff do a wipe on it; it's too much to correct manually.