Wow that is probably asking alot I was kinda hoping for the easy way!!
but I guess here are a few :
FED -
OBR - Official Baseball Rules
AMLU -
PBUC -
NFHS -
GD - In regards to Stance?
Some of those I know what they are but not the exact meaning. Also I think this would be a good post to constantly update so noobs like myself know what is going on when they come and can keep up with the conversation.