This appendix contains a listing of categories of heading entities with an indication of the field type and tag for each.  Categories marked X00, X10, X11, and X30 belong to the field types personal name, corporate name, conference name and title, respectively.  Categories marked X50 and X51 belong to the field types topical terms and geographic names.

 This listing is an alphabetical compilation of the separate lists of ambiguous headings provided under Input Conventions in the X00-X51 General Information sections.

 This list also appears in both the MARC 21 Format for Bibliographic Data and in the MARC 21 Format for Community Information.


Abbeys [X10]

Academies [X10]

Agoras [X51]

Airplanes, Named [X10]

Airports [X10]

Almshouses [X10]

Amusement parks [X51]

Apartment houses [X10]

Aquariums, Public [X10]

Arboretums [X10]

Archaeological sites [X51]

Areas and regions [X51]

Armories [X10]

Art works [X00, X10, X30]

Artificial satellites [X10]

Artists' groups [X50]

Asian conglomerate corporations [X10]

Asteroids (Individual) [X51]

Astronomical features (e.g., Comets, Galaxies, Planets) [X51]

Asylums (Charitable institutions) [X10]

Athletic contests [X11]

Auditoriums [X10]

Awards [X50]


Banks [X10]

Bars [X10]

Bathhouses [X10]

Baths, Ancient [X50]

Biblical characters, Named [X00]

Biological stations [X10]

Boards of trade (Chambers of commerce) [X10]

Botanical gardens [X10]

Boundary lines [X51]

Bridges [X51]

Broadcasting stations [X10]

Building details [X50]

Buildings, Private [X10]

Buildings occupied by corporate bodies [X10]

Bus terminals [X10]


Calderas [X51]

Camps [X51]

Canals [X51]

Capitols [X10]

Castles [X10]

Cathedrals [X10]

Caves [X51]

Celestial bodies [X51]

Cemeteries [X10]

Chapels [X10]

Churches (in use or in ruins) [X10]

Cities, Extinct (pre-1500) [X51]

City halls [X10]

City sections (entered directly) [X51]

City sections (entered subordinately, pre-AACR 2) [X10]

Civic centers [X10]

Clans [X00]

Club houses [X10]

Coal ash sites [X10]

Coliseums [X10]

Collections, Public or Private [X10]

Collective farms [X51]

Collective settlements [X51]

Colleges [X10]

Colloquia [X11]

Comets [X51]

Comic strips (established under title) [X30]

Communes [X51]

Communication satellites [X10]

Community centers [X10]

Competitions [X11]

Computer languages [X50]

Computer networks [X50]

Computer programs (established under title) [X30]

Computer systems [X50]

Concentration camps [X10]

Concert halls [X10]

Conservation districts [X51]

Contests [X11]

Convention centers [X10]

Convents [X10]

Correctional institutions [X10]

Countries, Groups of (e.g., Developing countries, Communist countries, Islamic countries, etc.) [X51]

Country clubs [X10]

Counts, Houses of [X00]

Courthouses [X10]

Crematories [X10]

Customhouses [X10]


Dams [X51]

Dance halls [X10]

Denominations, Religious (individual) [X10]

Deserts [X51]

Details, Building [X50]

Dispensaries [X10]

Docks [X51]

Doors [X50]

Dukes, Houses of [X00]

Dwellings [X10]

Dynasties [X00]


Earls, Houses of [X00]

Ecclesiastical entities that are also names of places (e.g., Basel (Switzerland : Ecclesiastical principality)) [X10]

Ecological stations [X10]

Economic zones [X51]

Educational institutions [X10]

Electronic discussion groups [X30]

Embassies [X10]

Esplanades [X51]

Estates [X51]

Ethnic groups [X50]

Events [X50] or [X11]

Exhibition buildings [X10]

Exhibitions [X11]

Expeditions, Military [X11]

Expeditions, Scientific [X11]

Experiment stations [X10]

Expositions [X11]


Factories [X10]

Fairs [X11]

Families [X00]

Farms [X51]

Feasts [X50]

Ferry buildings [X10]

Festivals and celebrations [X11]

Festivals, Folk [X11]

Fictitious characters [X50]

Fire stations [X10]

Folk festivals and celebrations [X11]

Forests [X51]

Fortresses (Structures) [X51]

Forts (Military posts, fortresses, etc.) [X51]

Free ports and zones [X51]

Funds [X10]

Funeral homes, mortuaries [X10]


Galaxies [X51]

Galleries [X10]

Games (Events) [X11]

Gardens [X51]

Gas fields [X51]

Gates [X50]

Geographic regions (e.g., Arctic regions, Tropics, etc.) [X51]

Geologic basins [X51]

Gods [X50]

Grain elevators [X10]

Grasslands [X51]

Groups of industries, Named [X10]

Gymnasiums [X10]


Halfway houses [X10]

Hazardous waste sites [X51]

Herbariums [X10]

Highways [X51]

Hill figures [X50]

Historic sites [X51]

Historical parks [X51]

Homes [X10]

Hospitals [X10]

Hotels [X10]

Houses (Families) [X00]

Houses (Structures) [X10]


Immigration stations [X10]

Individual works of art [X00, X10, X30]

Industrial groups, Named [X10]

Islands, Nonjurisdictional [X51]


Jurisdictions, Ancient [X51]


Laboratories [X10]

Lakes [X51]

Land grants [X51]

Legendary characters [X50]

Legendary dynasties [X50]

Libraries [X10]

Lighthouses [X10]

Lines, Boundary [X51]


Manors [X10]

Mansions [X10]

Market buildings [X10]

Marketplaces (Ancient) [X51]

Markets [X10]

Military installations (active; also all after 1899) [X51]

Mills [X10]

Mine buildings [X10]

Mines [X51]

Mints [X10]

Model railroads [X50]

Monasteries [X10]

Monuments (Structures, statues, etc.) [X50]

Moons [X51]

Morgues [X10]

Mortuaries [X10]

Motels [X10]

Motion pictures [X30]

Mountains [X51]

Movements, Social [X50]

Movie theaters [X10]

Museums [X10]

Music halls [X10]


Nebulae [X51]

Night clubs [X10]

Nuclear power stations [X10]

Nursing homes [X10]


Observatories [X10]

Ocean currents [X51]

Office buildings [X10]

Official residences [X10]

Old age homes [X10]

Olympic Games (as a heading) [X11]

Open spaces [X51]

Opera houses [X10]

Orders of Knighthood [X10]

Orphanages [X10]


Pagodas [X10]

Palaces [X10]

Parades [X11]

Park districts [X51]

Parks [X51]

Pipelines [X51]

Plains [X51]

Planetariums [X10]

Planets [X51]

Plans (Programs) [X10]

Plantations [X51]

Playgrounds [X51]

Plazas (Open spaces, squares, etc.) [X51]

Police stations [X10]

Poorhouses [X10]

Port authorities [X10]

Ports (Physical facilities) [X51]

Post offices [X10]

Power plants [X10]

Presidential mansions [X10]

Prisons [X10]

Programs [X10]

Projects [X10]

Public celebrations, pageants, anniversaries [X11]

Public comfort stations [X10]

Pueblos [X51]

Pyramids [X50]


Races (Contests) [X11]

Racetracks [X10]

Radio programs [X30]

Railroad models [X50]

Railroad tunnels [X51]

Railroads [X10]

Railway stations [X10]

Ranches [X51]

Recreation areas [X51]

Recreation districts [X51]

Refugee camps [X51]

Regions, Geographic (e.g., Arctic regions, Tropics, etc.) [X51]

Religious denominations [X10]

Research stations [X10]

Reservations, Indian [X51]

Reserves (Parks, forests, etc.) [X51]

Reservoirs [X51]

Resorts [X10]

Restaurants [X10]

Rivers [X51]

Roads [X51]

Rooms [X50]

Royal houses (Families) [X00]


Sanatoriums [X10]

Sanitary landfills [X51]

Sanitation districts [X51]

Satellites (i.e. Moons) [X51]

Satellites, Artificial [X10]

School districts [X10]

Schools [X10]

Schools of artists [X50]

Seas [X51]

Seminars [X11]

Service stations [X10]

Shipyards [X10]

Shopping centers [X10]

Shows (Exhibitions) [X11]

Shrines (not churches) [X50]

Social movements [X50]

Software, Computer (established under title) [X30]

Sound recording labels [X10]

Space vehicles [X10]

Spas [X10]

Sports arenas [X10]

Sports events [X11]

Squares [X51]

Stadiums [X10]

Stars (Individual) [X51]

Stars (Types) [X50]

Statues [X50]

Steppes [X51]

Stock exchanges [X10]

Stores, Retail [X10]

Streets [X51]

Structures (nongeographic, e.g., towers) [X50]

Studies (Research projects) [X10]

Stupas [X50]

Symposia [X11]


Television programs [X30]

Temples (in use or in ruins) [X10]

Terminal buildings [X10]

Tests [X50]

Theater buildings [X10]

Theater companies [X10]

Tombs [X50]

Tournaments [X11]

Towers [X50]

Trails [X51]

Tribes (as legal entities only) [X10]

Tribes (Ethnic groups) [X50]

Tunnels [X51]


U.S. National Park Service, U.S. Forest Service, and U.S. Fish and Wildlife Service units named after a park, forest, etc. [X51]

Undertakers [X10]

Universities [X10]

Utility districts [X51]


Valleys [X51]

Villas [X10]


Walls [X50]

Warehouses [X10]

Water districts [X51]

Waterways [X51]

Wildlife refuges [X51]

Works of art [X00, X10, X30]

Workshops [X11]


Zaibatsu [X10]

Zoos [X10]

See also: