Definitive source for abbreviations used in certificate DN's

Can someone please point me to a definitive source document, 
that defines the official abbreviations used within X.509 digital 
certificate DN's?   For instance, which specific document 
specifies that the abbreviation S must be used for State, G (or 
is it GN?) must be used for GivenName, SN for Surname, etc.  
Thank you.

Arshad Noor
StrongAuth, Inc.

P.S.  I have looked at ITU-T's X.520 (02/2001) document and while 
it shows some abbreviations (CN, S, L, T, etc.) it does not elucidate 
all of them.