Identitymanagement and Sex

I learned something this morning. There is an ISO norm (ISO-5218:2004) that defines the representation of human sexes in IT systems "Codes for the
representation of human sexes". Probably there is an ISO norm for everything?

The actual representation looks similar to what is defined in the OASIS Identity Metasystem Interoperability standard.

0 - Not known
1 - Male
2 - Female
9 - Not applicable

IMI does not reference ISO-5218:2004 and "0 - Not known" is something different than "0 - unspecific". I guess the authors of the IMI spec do not know the ISO norm. Or is this due to the English differentiation of "sex" and "gender"? The ISO norm defines "sexes" and the IMI standard defines "Gender".
Interesting is the sheer number of "standards" to represent gender/sex.
http://de.wikipedia.org/wiki/Datenstandards_zur_Beschreibung_des_Geschlechts
(I have not found this in the English version of Wikipedia; Sorry.)
I find it interesting too that "transgender male" and "transgender female" do not exist in many standards. Although it may be inappropriate or even illegal to store the transgender information in a database but this is not the issue. Somebody might want to prove that he was formerly a she. It is better to have a representation in a norm/standard for all cases. The legal issues are outside the standard. ("legal" is always a path to headache for me e.g. http://de.wikipedia.org/wiki/Transsexuellengesetz)
OASIS should always check that new OASIS standards might be aligned to older existing standards.
I think the "gender" section of the IMI standard should be revised.