AA: Armagh Ancestry
AC: Ancestry.com
ACM: Armagh County Museum
AO: Assay Office
APGI: The Association of Professional Genealogists in Ireland
BBHC: Bru Boru Cultural Centre
BCL: Belfast Central Library
BELB: Belfast Education and Library Board
BFHS: Ballinteer Family History Society
BL: The British Library
BPL: Bray Public Library
BPMA: The British Postal Museum and Archive
Butler Library: Butler Library
CACL: Carlow Central Library
CCCA: Cork City and County Archives
CGP: Carlow Library Genealogy Service
CGS: Cork Genealogical Society
CHGC: Cavan Genealogy
CICE: Church of Ireland College of Education
Clare HGC: Clare Heritage and Genealogical Centre
CLCL: Clare County Library
CLHS: Clogher Historical Society
COCIL: Cork City Libraries
COCL: Cork County LibraryCork County Library and Arts Service
CTFL: Cardinal Tomas O Fiaich Library
CVCA: Cavan County Archives
CVCL: Cavan County Library
DA: Donegal Ancestry
DAS: Donegal Archives Service
DCLA: Dublin City Library and Archive
DDA: Dublin Diocesan Archive
DDC: databases.dublincity.ie
DGC: The Genealogy Centre
DHG: Dublin Heritage Group
DL: Downpatrick Library
DLHS: Dun Laoghaire Heritage and Genealogy
DLRCL: Dun Laoghaire Rathdown County Library
DOCL: Donegal County Library
DSHGC: Dun na Si Heritage and Genealogical Centre
DUCL: Dublin City Libraries
EGFHS: East Galway Family History Society Ltd
FHL (LDS): Family History Library (Latter-Day Saints)
FHL (LDS): LDS Family history library
FHL (LDS) NI: Family History Library (Latter-Day Saints) N.I.
FICL: Fingal County Library
FIHS: Finuge Heritage Society
FMP: FindMyPast.ie
FRC: Family Records Centre
FS: FamilySearch
GA: Garda Archives
GCL: Galway County Library
GFHSW: Galway Family History Society West Ltd
GIHS: Great Island Historical Society
GO: The Genealogical Office
GPL: Galway Public Library
GRO: General Register Office (Dublin)
GRO (England): General Register Office (London)
GRONI: General Register Office (Belfast)
GRONI: NI General Register Office
GSI: Genealogical Society of Ireland
HSP: The Historical Society of Pennsylvania
IFHS: Irish Family History Society
Igen: IrishGenealogy.ie
IGRS: The Irish Genealogical Research Society
IMA: Irish Midlands Ancestry
IRRS: Irish Railway Record Society
IW: Irish World Heritage Centre
JHA: James Hardiman Library
KECL: Kerry County Library
KG: Kildare Genealogy
KICL: Kildare Library and Arts Service
KKCL: Kilkenny County Library
LACL: Laois County Library
LC: Local custody
LCA: Limerick City Archives
LCA: Longford County Archives
LCIL: Limerick City Library
LCP: Local Catholic parish
LECL: Leitrim County Library
LeGC: Leitrim Genealogy Centre
LG: Limerick Genealogy
LGC: Longford Genealogy Centre
LHL: Linen Hall Library
LICL: Limerick County Library
LoC: Library of Congress
LOCL: Longford County Library
Louth County Archives: Louth County Archives
LTCL: Louth County Library
LVO: Land Valuation Office
MCM: Monaghan County Museum
MG: Monaghan Genealogy
MHA: Maritime History Archive
MHC: Mallow Heritage Centre
MHCL: Meath County Library
MHGC: Meath Heritage and Genealogy Centre
ML: The Mercer Library
MNCL: Monaghan County Library
MNFHRC: Mayo North Family History Research Centre
MOCL: Mayo County Library
MSFHC: South Mayo Family Research Centre
NAI: National Archives of Ireland
NEELB: North Eastern Education and Library Board
NIFHS: North of Ireland Family History Society
NLA: National Library of Australia
NLC: National Library of Canada
NLI: National Library of Ireland
NLNZ: National Library of New Zealand
NLS: National Library of Scotland
NLSA: National Library of South Africa
NTGC: North Tipperary Genealogy Centre
OCL: Offaly County Library
OPW: Office of Public Works
PHS: Presbyterian Historical Society
PRONI: Public Record Office of Northern Ireland
RCBL: Representative Church Body Library
RCL: Roscommon County Library
RD: Registry of Deeds
RHGC: Roscommon Heritage and Genealogy Company
RHK: Rothe House Trust Ltd
RHS: Raheny Heritage Society
RIA: Royal Irish Academy
RSAI: Royal Society of Antiquaries of Ireland
SCL: Sligo County Library
SDCL: South Dublin County Library
SEELB: South Eastern Education and Library Board
SELB: Southern Education and Library Board
SFL: Society of Friends Library
SHC: Swords Historical Society
SHC: Skibbereen Heritage Centre
SHGS: Sligo Heritage and Genealogical Society
SOF (NI): Society of Friends Library (N.I.)
TCD: Trinity College Dublin
TCL: Tipperary County Library
TFHR: Tipperary Family History Research
THC: The Central Library
TNA: The National Archives
UCDA: University College Dublin Archives
UHF: Ulster Historical Foundation
WCHC: West Cork Heritage Centre
WELB: Western Education and Library Board
WFHC: Wicklow Family History Centre
WHCL: Westmeath County Library
WHGC: Waterford Heritage
WHGS: Co. Wexford Heritage and Genealogy Society
WICL: Wicklow County Library
WXCA: Wexford County Archive
WXCL: Wexford County Library