This should be an implication, not an alias, if that at all.
Most internal shots do feature a womb, but not all. I've used 'womb' to search for specific things before... particularly deep penetration, cervical penetration, and a few others things that we don't have particularly well traveled tags for.
While it'd be nice to get those other sorts of tags filled out and unify the existing tags a bit more, I'm not sure the time is right for this alias, or implication, to ocme into existance just yet.
Updated by anonymous