@Arch: The article was from April 2011, but the one that Andy posted was from September, so I think they are currently NOT doing no-match letters.
I did need identification papers, but I just handed in my college ID which has no gender marker and my birth cert, but my papers were collected in a big pile with like 12 other people's papers, so I doubt my employer noticed. He didn't give me any strange looks or anything when handing it back, and he's pretty lax about rules and things like that, so I doubt he did more than glance over it.