I spent a fair amount of time thinking about this and the character of antimemes. Even ended up writing a whole taxonomy and mathematical framework for it.
In general a meme is specific to an entity-pair, with self-censoring information as a subset of antimeme that makes the information itself remove itself from the mind that learns it. In general though, information that is an antimeme is not the same thing as a category of information that describes an antimeme.
So, "your parents weird sextape" is generally antimemetic, you are unlikely to share that information yourself and I would not expect to see many examples where someone posted this. Your password is also antimemetic in most cases.
That said, information may contain both antimemetic and memetic components, such as "the game" (I just lost). The rules inherently are antimemetic and self-censoring, however the memetic component ensures this is still transmitted effectively to as many people as possible. A more entity-pair specific meme-antimeme relation is "where the good drug dealers hang out", which is information that is highly memetic or antimemetic under different conditions.
I think the key isn't to think of these things as strict categories, but labels we ascribe to a more continuous measure of memeablity.