This article shows that limiting sex definitions to just male and female can cause problems when there is an acknowledged but undefined third sex. Voter registration forms seem to be the current problem as Hijras are refusing to check if they are male or female. It seems like, especially in India, it would be easy to edit forms to include hijras, officially recognize them and then get an idea of how many there are in the country. It seems logical, but think of all the work it would take to do that we know it won't happen. Until then, enjoy the stories of people who refuse to be defined as either male or female.
This is just another example of how language can expand our world, but can limit it as well.