I know the phrase "tag what you see, not what you know" is essentially the motto of this site, and that canon does not matter in this rule. There was a post by Powfooo of a character called Mio which has always been shown as a crossdressing male in his other posts, but the admins and privilged asserted that it was female because of her clothes and features. When I asked if I should tag characters like Etheras as female if there is no indication of male in the photo, the admin said yes.

So, I was wondering if we tag incest on posts. If there is a post of Bambi and the Great Prince of the Forest having sex, and Bambi does not call him dad or father while GPF doesn't call him son, aren't we relying on prior knowledge to tag that as incest?

What should I do?

Hello Cyenz,

Interesting question, because the wiki gives no hints. According to the information, only TWYK would remain. However, I do not know what the rules say, but theoretically, you would call it only as incest, when it is seen in the text or image they are related. To see, example by a family photo, I would say.

However, I once said to me a user with low rank (privileged), the gender specified on model sheets (Written) are not relevant as they might have been edited. So you could also assume that the text is not relevant, because if it is not allowed in the modelsheet to refer to the gender by means of the picture statement, it would be wrong with incest. But is only a guess.

Make it like an admin to me again and again says: In doubt, let it be. Or ask an admin directly.

There had been a thread about it here: https://e621.net/forum/show/209445

If I upload an incest pic, I always tag it as such. It just makes sense to me, and the worst that can happen is that the tag might later be removed. But there are over 10,000 submissions tagged as incest, so I doubt that unless the submission is really un-obvious about it, that the admins are going to remove the tag. Go ahead and tag it that way if you know it's accurate.