Are tags like "incest", "mother_and_son", "father_and_daughter", etc. appropriate if the two characters look nothing alike and are only related canonically?

I see this often with such tags - for example, when the TMNT turtles are in a picture with the rat guy who's canonically their dad.

Characters who are identifiable, such as Master Splinter and the mutant turtles, I'd say it's fine, but in cases where it's just generic characters from a species, for example latios and latias, then not unless it's stated in the picture.

yeah the incest tags are kinda lenient but they have limits too. so like if the visual clues are outright conflicting against the incest tag, it should not be tagged as such. like you got red feral unicorn with blue eyes who is supposedly dad of a white green eyed anthro rabbit, it probably should not be getting incest tag

also there is technical incest tag for cases like adopted children