Not sure what kind of joke

Actuall yes, Mcdonaldo, MTF trans girls.

*actually. and I meant physically. sorry if I caused any offence :)

Physical doesn't matter, if they identify as a girl, body parts don't matter. And is everyone on this site a freaking grammar nazi?

No. Gender is technically determined genetically. If they have a Y chromosome (1 or more), they're considered male. No testicles or penis? Have tig ol' bitties? No problem! You're still a guy. No Y chromosome? Got cockn'balls? Sorry, you're still a lady. It doesn't matter which gender they identify themselves with, it's purely nature that determines it. They can WANT to be and ACT like the opposite gender, but they'll never be genetically.

They don't just want it, they don't just act. They are truly born in the wrong body.

Exactly! There's nothing wrong with identifying with and acting as the opposite gender, but there is a problem by trying to PROVE that you're the opposite gender.