Here's a list of the meaning of a few of the abbreviations which are sometimes used on this list.

AF = Ancestral File (Morman ancestral database)
BDM = Births, Deaths, and Marriages
BVRI = British Vital Records Index (a set of searchable Genealogy CD's from http://www.familysearch.org)
CD = Compact Disk
C of I = The Church of Ireland
FHC = Family History Centre (Genealogy Centers operated by the Mormon Church)
GRO = General Register Office (in Dublin)
GV = Griffith's Valuation
IGI = International Genealogical Index (on line at http://www.familysearch.org)
IGSI = Irish Genealogical Society International http://www.rootsweb.com/~irish/
ISTG = Immigrant Ships Transcribers Guild
LDS = Latter Day Saints (Mormon)
PRONI = Public Record Office of Northern Ireland
RC = Roman Catholic
SKS = Some kind soul
TIA = Thank you/Thanks in advance
TTYL = Talk to you later
W.D.T.L. = Who Departed This Life

Hope these abbreviations help.

Best wishes,
Tony Riordan