Thoughts about VCard4 GENDER
This is about the VCard 4 GENDER field (which is used in VCards for storing contact information, CardDAV synchronization etc.) and why and how it could be improved.
Current status: biological sex and binary options
Most importantly, its main component refers to biological sex, which just not belongs in a VCard¹. In business card/VCard context, only the gender may be of interest (to address people etc.). But according to the standard, GENDER:F now means "biological sex [whatever this exactly means] = female", and this is not what one would expect from this property ("gender = female").
The second component refers to gender identity and is a free-form text (which is fine, but I haven't seen an implementation to actually use it).
In some real implementations, "gender" and "(biological) sex" are used interchangeably and most ones have only "male" and "female" options (and no option for non-binary people), although the standard defines M (male), F (female), O (other), N (none / not applicable) and U (unknown) values (for biological sex).
Suggestions: GENDER means gender, and non-binary genders exist
In a first thought about how to improve it, my suggestion would be GENDER:<- (unknown/not applicable/prefer not to say)/F/M/NB/mandatorily supported free-form-text> (if the gender is of interest at all) to store gender identity (not biological sex or legal assignment, plus probably a way to store pronouns and how to address people (all with support for the already defined LANGUAGE parameter).
¹ apart from that there is no biological sex, but only biological facts related to sex like sex chromosomes, hormone levels, existence and shape of genitals and other body parts, fertility etc. Most people do not have their sex chromosomes, sex hormone levels etc. tested.