'I don't do that, in support of those who have not yet made their decision - requiring a public statement could force those who haven't decided yet, to either prematurely out themselves, or lie about themselves for protection.'
'No thank you, it would be like being required to add 'I believe in God the father, God the son, etc' on my emails. I don't share that belief system either, and belief is of course a protected characteristic.'
When faced with a form asking your 'gender', go for Other - and if there is a freestyle box, add in 'I do not have a gender. My sex is ...'
'I don't agree with imposing compelled speech. I abstain.'
'No.'
What would you do?