Cross dressing, of course.

From here:

As U.S. politicians continue to debate whether to let gays serve openly in the American military, the Canadian Forces have issued a new policy detailing how the organization should accommodate transsexual and transvestite troops specifically. Soldiers, sailors and air force personnel who change their sex or sexual identity have a right to privacy and respect around that decision, but must conform to the dress code of their “target” gender, says the supplementary chapter of a military administration manual.