Some of your listings have SIG, ALS, LS, ANS, etc. What do these mean?

SIG: Signature
ALS: Autograph Letter Signed; entirely in the hand of the author
LS: Letter Signed; signed by the author but written by another (i.e. a secretary or clerk)
TLS: Typewritten Letter Signed
ANS: Autograph Note Signed; same as ALS but more brief.
ADS: Autograph Document Signed; (a will, a manuscript, a journal) but signed by the author
DS: Document Signed (such as a check or court record)
AQS: Autograph Quotation Signed; this could be poetry or a memorable statement; in the handwriting of the author. Many autograph albums of the mid 19th Century contained brief signed quotations
AES: Autograph Endorsement Signed; endorsement in the author’s hand, usually on the verso or margin of another letter
AMuQS: Autograph Musical Quotation Signed; this might be a few bars of music from the composer’s body of work, which he has signed and/or dated. These are highly desirable collectibles.
SP: Signed Photograph
ISP: Inscribed Signed Photograph; this is the same as above but includes a dedication or a few words of greeting in the hand of the author.
MEM: Memorabilia
NY: No year
ND: No date
NP: No place
PP: Pages