HRT is sometimes specified as HT. Just as Hormone Therapy
some others:
AMAB - Assigned Male at Birth
AFAB - Assigned Female at Birth
FFS - Facial Feminization Surgery
GCS - Gender Confirming Surgeries (there are, to some, different meanings)
- to me, it means all surgeries relating to transition (face, top, bottom, ...)
- to others, it means bottom surgery
SRS - Typically bottom surgery
BA - Breast augmentation
MtF - Male to Female transition
FtM - Female to Male
RLE - Real Life Experience (think of this as Full-Time but early on. Some countries require RLE before surgery and I think in some cases before Hormones.)
DVT - Deep Vein Thrombosis (blood clots in the legs [typically I think])
E - Estrogen
T - Testosterone (Personally this is Evil stuff

)
AA - Anti Androgen (T-BLockers such as Spiro and I think Finasteride)
IM - Inner Muscular (Taking hormones via shots)
Passing - being able to walk up to someone and they see you as the person you are transitioning towards,
Clock-ing/ed - Someone who notices your transgender status and in some cases points it out.
Top surgery - typically for FtM the removal of the breast material to make a flat chest. MtF typically are referring to BA
I'm sure there are twice as many (or more) but this should help get you started.