DC - Daniel Clowes

ANLL - All New Lloyd Llewellyn Special  
ASC - Art School Confidential [this abbreviation refers to the film]
C - Caricature  
DB - David Boring  
E - Eightball  
GW - Ghost World   
IH - Ice Haven 
LVG - Like a Velvet Glove Cast in Iron  
LL - Lloyd Llewellyn 
LR - Lout Rampage! 
MWLL - The Manly World of Lloyd Llewellyn  
OB - Orgy Bound  
OLLC - #$@&!: The Official Lloyd Llewellyn Collection   
P - Pussey!  
TCE - Twentieth Century Eightball
MW - Mister Wonderful
TDR - The Death-Ray

[A] - art by DC
[A:] - art by the person whose name appears after the colon
[W:] - written by the person whose name appears after the colon
[W/A] -writer and artist is DC
VA - various artists
HC - hardcover
PB - paperback 
s&n - signed and numbered
ed. - edition of {the number of items produced}
b/w - black and white
clr - color

(c.) - circa  [the date is approximate]
(nd) - no date  [the item is not dated]
(?) - the date is unknown
(UC) - uncollected

Other abbreviations are explained when used.