@glowingdemon Actually, shemales are generally considered to be a subset of futanari; they're females with a dick instead of a pussy, rather than in addition.
@FarkyMac I'm Japanese, and shemales/newhalves aren't a subset of futanari. A shemale has only a male reproductive system while a futanari has both female and male reproductive systems. If anything a shemale is a subset of a male in reproductive structures but a subset of a female in terms of body form whereas a futanari is a subset of hermaphrodites in reproduction but a subest of a female in terms of body form. Futanari is after all defined as a feminine hermaphrodite as opposed from a masculine hermaphrodite.
A shemale by all means of biological reproduction/biology is male in the objective sense. However, through sociology a shemale may be considered female via social/cultural perspective through the subjective sense. It's like a mind vs body sorta thing.
As to the tagging, futanari and shemale are both used on this site for tagging purposes. These tags have definitions which separate shemales from futanari via the presence of a vagina. Though some people don't care about such separation, many in the Japanese scene do if only to be so by simple preference.