How exactly does someone "identify" as male or female?

The other day I saw an ad for some event which was advertised as being only for people who "identify as female." This wording struck me as kind of odd. What does it take to identify as a female (or male for that matter)? If I'd gone in and told them I identify as female, could they actually keep me out? How do they know what I "identify" as to know if I'm telling the truth (unless they catch me lying, which isn't likely unless someone knows me)? Does it matter that I have facial hair? Would I have to act "feminine?"

This is semi-hypothetical, as I did really see an ad for an event (I've forgotten exactly what the event was now) but have no intention of going, but the thought did occur to me as to how exactly it's determined you identify as female or male.

?2014-03-31T16:53:13Z

Pre-op transgender people would be one gender but identify as the other.

Essentially you know whether you are male or female. You could lie about it I suppose, if you are that kind of person. I don't see any value in doing so.

Arch2014-03-31T17:23:52Z

If you "feel" female, then you identify as female regardless of your anatomy. Likewise, if you "feel" male, then you identify as male even if you are currently pregnant.

I've decided that I "identify" as feLINE. Now, I expect to be exempt from Obamacare, and should be able to get all my medical care at the local veterinarian clinic.

Elsa2014-03-31T17:02:23Z

What a world we live in. You don't know if you are female or male? Stand in front of a mirror totally naked. That will tell you.
So much sexual education today and people don't even know if they are females or males? Hard to imagine. Not to mention sad.

ʄaçade2014-03-31T16:53:11Z

If you see a grant or scholarship or subsidy reserved for people who "identify" as female, you simply declare yourself to be female long enough to fill out the form and collect the money.

If you see a sign that says: "Free entrance for people who identify as male", then simply declare yourself to be male long enough to get through the door.

If Gender is a "Social Construct", then we can construct ourselves as we see fit from moment to moment.

... so convenient.