It's understandable that if you're not GNC or a FAAB, you might not even know what the first part of this sentence means. But that's why this list is here — to introduce you to these nine gender and sexuality acronyms you might not know about! Hopefully you will take them into account next time you're looking for a more inclusive — or more specific — term to use in regular conversation.
Gender Non-Conforming, where one's gender norms or gender expression do not match the male/female traits expected by society. ("Trans*" or "transgender" is sometimes used interchangeably with GNC, but more often refers to one's gender expression or identity being inconsistent with the one assigned at one's birth.)
Men who have sex with men, a term used in the medical and social sciences to describe males who have sex with other males. This term is especially useful because it does not specify one's sexual identity (e.g. gay).
Cross-dressing, where one wears clothing and other items contrary to one's societal gender norms. A person who cross-dresses does not necessarily identify as trans*, since cross-dressing alone does not signify one's gender identity.
Male-assigned at birth/female-assigned at birth/unassigned at birth, when one is sexed as female, male, or unassigned. All three are generally assigned by the physician present at birth based on the person's genitalia. For example, the term "FAAB" could be used by a transgender man to denote that he was assigned the female sex at birth.
Coercively assigned male/female at birth, used by GSM/GNC individuals as well as intersex people to describe how they were sexed at birth. In the case of intersex individuals — those with incompatible outer and inner genitalia — these acronyms could refer to the fact that the person did not have a choice in their sexing, or that they had surgery to "correct" the discrepancy (removing the "male" or "female" set of genitalia).
Trans-exclusionary radical feminists, a group of feminists claiming that trans women aren't really women and thus exclude them from their cause. One TERF in particular, Victoria Brownworth, has gone so far as to say that "the role of male-to-female transsexuals in the women's movement as a whole and the lesbian movement in particular ... [is] the ultimate in male power-tripping."
Queer/Questioning, Undecided, Intersex, Lesbian, Transgender/Transsexual, Bisexual, Allied/Asexual, Gay/Genderqueer, considered to be a more exclusive acronym than LGBT — plus, it's easy to remember and fun to say.
And, to tie this in with popular current events...
Same-sex marriage, not to be confused with the popular-but-less-inclusive "gay marriage." Same-sex marriage means that anyone — whether they be gay, lesbian, bisexual, pansexual, etc. — can marry someone of the same sex. Gay marriage, on the other hand, has always been legal (in one way). All it involves is someone who identifies as gay getting married, which could mean a gay man marrying a woman.