Optional ♂ or ♀

[Mirage]

And what if you put the female sign up when you are in reality a male?

Do you want SE to check each player individually? Do you want them to decide your gender based on the name on the credit card you pay with? If so, what if a 17 year old girl pays with her dad's CC?

Or what if someone has an unisex name (like Robin or Casey), how will SE know what your gender is, will they call you and decide based on your voice?