Acronyms?

[Lilfae]

Hi!
I am fairly new here, and I've been reading a few posts around the different threads and boards. But sometimes there are acronyms or shortening of words into a few individual letters much like PTSD and C-PTSD...
And I find these very difficult to understand or translate into what they actually mean. The only example I have at hand is "FOO".
Could you guys write a list of what they are and what they mean? English is my third language

[Three Roses]

http://www.outofthestorm.website/acronyms/

[Lilfae]

Thank you!