Here are some common terms used in the world of autograph collecting and what they mean:
TTM - Through the mail, autograph obtained by writing to a celebrity
IP - In Person ie: in person autograph
AP - Auto pen a device which signs autographs with a pen, ie not signed by a person
Via Venue - Request was sent to somewhere the celebrity was appearing/playing
Pre Print - Autograph is part of the photo ie: like a photo copy
Sec - Secritarial autograph signed by secretary, agent etc.. and not the acutal celebrity (a few stars that do this are Al Pacino, Robert DeNiro, Sarah Jessica Parker, Doris Day, Colin Farrell, John Travolta & many more - there is a very long list of people who do this so always do your research before sending)
Stamped Autograph - Autograph provided is from a rubber stamp not a person
Studio Fan Mail - A company used by stars to send out pre print autogrpahs on their behalf
LOR - Letter of request
SSAE - Stamped self addressed envelope