Yes, but there is a difference. If the tag is used to say, "hey, I want an informed, gender specific response to this post" then it may be a valid tag. Not all posts beg such types of responses. For example, you could post this: http://hubski.com/pub?id=131056 and tag it #byyski and ask in the text "Fathers of Hubski do you help inform your children's diets or does this fall largely to the mother?" -Bad example, but you get the point.