Those of us in the autograph collecting hobby have some terminology which we use interchangeably when we discuss autographs. These are helpful "shorthand" terms to use when discussing autographs and collecting them.
The Most Common Definitions:
ALS - Autograph Letter, Signed: This is a letter written in the celebrity's own hand, usually a short note.
AMQS - Autograph Musical Quotation, Signed: A piece of music, a bar of music or some musical notes, signed in the celebritiy's hand.
ANS - Autograph Note, Signed: This is a short note, written in the celebrity's own hand.
AQS - Autograph Quotation, Signed: This is a quotation, handwritten by the celebrity.
C - Color: Self-explanatory
CS - Card, signed: Generally, a 3-inch by 5-inch card, signed by the celebrity. Also shown as SC.
DS - Document, Signed: Any item, such as a contract, deed, or formal letter, signed by the celebrity.
FDC - First Day Cover: A philatelic item, usually an envelope, which has a special postmark for a first-day-of-issue stamp. Many FDC's have custom artwork.
HOF - Hall of Fame: Usually associated with sporting celebrities, the Hall of Fame is an official museum dedicated to that particular sport.
I - Inscribed: Personalized to an individual. I.E., "To Joe..."
ISP - Inscribed, Signed Photo: A common definition, this denotes an inscription or personalization on a photograph. Sometimes listed as SPI or IPS.
LS - Letter, Signed: Generally, a letter written by a secretary, but signed by the celebrity.
MOC - Member of Congress: Any elected Representative or Senator sitting, or past-sitting, on the United States Congress.
MOH - Medal of Honor: Used to denote a recipient of the Medal of Honor, the highest award in the United States Military, given for exceptional bravery under fire which results in an exceptional act. Also written as CMOH.
SIG - Signature: Usually a signature, by itself, on a piece of paper.
SP - Signed Photograph: A signature on a photograph. Also written as PS.
TCS - Trading Card, Signed: A celebrity signature on a trading card. Most popular with sports autograph collectors.
TLS - Typed Letter, Signed: A letter which is typed and signed by the celebrity.
Types of non-authentic signatures:
Secretarial: A signature of the celebrity, signed by the celebrity's agent, assistant or secretary.
Pre-Printed: Any signature which is printed on the negative and then printed as part of the photo.
Rubber Stamp: Any signature which is applied to an item with a rubber stamp.
Autopen: A mechanical device which prints a signature on an item, rather than an actual signer.
Forgery: Any unauthorized copy of a signature, passed off as the real thing. Not to be confused with a secretarial, which is an authorized copy.