It is not reserved exclusively for the disabled. Not all disabilities are visible.Doesn't seem right for an able bodied person to use a disabled toilet, not saying you can't.
In the building I sometimes manage, I encourage, for example, a father accompanying a small daughter, to take her into the non-specific facilities rather than into the men's or the women's ones.
Some might think that a man who believes himself to be a woman has a problem of some kind.
