Some commonly used abbreviations on forums, blogs, and Youtube.

Lengths  SL- Shoulder Length, APL- Armpit Length,  BSL- Bra Strap Length, WL- Waist Length

Transitioning- BC- Big Chop

Afro TWA- Teeny Weeny Afro, BAA-Big Ass Afro

Others: EVOO- Extra Virgin Olive Oil

Thats all I can think of right now