There are 999 possible MARC tags, many of which have been established by the Library of Congress as fields in the various MARC formats.  The following lists each possible tag and, where applicable, its assigned usage in the Authority Data Format.

The Tag List groups the Variable Control Fields and Variable Data Fields.  The Variable Data Fields are subgrouped as follows:

Numbers and Codes

Complex Name References

Headings

Notes

Complex Subject References

Heading Linking Entries

See From Tracings

Other Variable Fields

See Also From Tracings

Locally Defined Fields

Series Treatment

 

Note:  Generally, any field containing a "9" (e.g., 049, 910, etc.) is available for local use, such as local call numbers, holdings, or subject headings.  Check with your system vendor for further information.

Leader and Directory:

Leader

Directory

Variable Control Fields:

001  Control Number  (NR)

002  unassigned

003  Control Number Identifier  (NR)

004  unassigned

005  Date and Time of Latest Transaction  (NR)

006  unassigned

007  unassigned

008  Fixed-Length Data Elements  (NR)

009  unassigned

Variable Data Fields:

Numbers and Codes:

010  Library of Congress Control Number  (NR)

011 - 013  unassigned

014  Link to Bibliographic Record for Serial or Multipart Item  (R)

015  unassigned

016  National Bibliographic Agency Control Number  (R)

017 - 019  unassigned

020  International Standard Book Number  (R)

021 unassigned

022  International Standard Serial Number  (R)

023 unassigned

024  Other Standard Identifier  (R)

025 - 030  unassigned

031  Musical Incipits Information  (R)

032 - 033  unassigned

034  Coded Cartographic Mathematical Data  (R)

035  System Control Number  (R)

036 - 039  unassigned

040  Cataloging Source  (NR)

041  unassigned

042  Authentication Code  (NR)

043  Geographic Area Code  (R)

044  unassigned

045  Time Period of Heading  (NR)

046  Special Coded Dates  (R)

047 - 049  unassigned

050  Library of Congress Call Number  (R)

051  unassigned

052  Geographic Classification  (R)

053  LC Classification Number  (R)

054  unassigned

055  Library and Archives Canada Call Number  (R)

056 - 057  unassigned

058  LC Classification Number Assigned in Canada  [obsolete]  [CAN/MARC only]

059  unassigned

060  National Library of Medicine Call Number  (R)

061 - 062  unassigned

063  NLM Classification Number Assigned by NLM  [obsolete]  [CAN/MARC only]

064  unassigned

065  Other Classification Number  (R)

066  Character Sets Present  (NR)

067  unassigned

068  NLM Classification Number Assigned in Canada  [obsolete]  [CAN/MARC only]

069  unassigned

070  National Agricultural Library Call Number  (R)

071  unassigned

072  Subject Category Code  (R)

073  Subdivision Usage  (NR)

074  unassigned

075  Type of Entity  (R)

076 - 079  unassigned

080  Universal Decimal Classification Number  (R)

081  unassigned

082  Dewey Decimal Call Number  (R)

083  Dewey Decimal Classification Number  (R)

084 - 085  unassigned

086  Government Document Call Number  (R)

087  Government Document Classification Number  (R)

088  Document Shelving Number (CODOC)  [obsolete]  [CAN/MARC only]

089  unassigned

09X  Local Call Numbers

Headings:

100  Heading - Personal Name  (NR)

101 - 109  unassigned

110  Heading - Corporate Name  (NR)

111  Heading - Meeting Name  (NR)

112 - 129  unassigned

130  Heading - Uniform Title  (NR)

131 - 139  unassigned

140  Uniform Title  [obsolete]  [CAN/MARC only]

141 - 142  unassigned

143  Collective Title  [obsolete]  [CAN/MARC only]

144 - 146  unassigned

147  Heading - Named Event  (NR)

148  Heading - Chronological Term  (NR)

149  unassigned

150  Heading - Topical Term  (NR)

151  Heading - Geographic Name  (NR)

152 - 154  unassigned

155  Heading - Genre/Form Term  (NR)

156 - 161  unassigned

162  Heading - Medium of Performance Term  (NR)

163 - 179  unassigned

180  Heading - General Subdivision  (NR)

181  Heading - Geographic Subdivision  (NR)

182  Heading - Chronological Subdivision  (NR)

183 - 184  unassigned

185  Heading - Form Subdivision  (NR)

186 - 199  unassigned

200 - 259  unassigned

260  See below

261 - 299  unassigned

300 - 334  unassigned

335  Extension Plan  (R)

336  Content Type  (R)

337 - 347  unassigned

348  Format of Notated Music  (R)

349 - 359  unassigned

360  See below

361 - 367  unassigned

368  Other Attributes of Person or Corporate Body  (R)

369  unassigned

370  Associated Place  (R)

371  Address  (R)

372  Field of Activity  (R)

373  Associated Group  (R)

374  Occupation  (R)

375  Gender  (R)

376  Family Information  (R)

377  Associated Language  (R)

378  Fuller Form of Personal Name  (NR)

379  unassigned

380  Form of Work  (R)

381  Other Distinguishing Characteristics of Work or Expression  (R)

382  Medium of Performance  (R)

383  Numeric Designation of Musical Work  (R)

384  Key  (NR)

385  Audience Characteristics  (R)

386  Creator/Contributor Characteristics  (R)

387  unassigned

388  Time Period of Creation  (R)

389 - 399  unassigned

Complex Subject References:

260  Complex See Reference - Subject  (R)

360  Complex See Also Reference - Subject  (R)

See From Tracings:

400  See From Tracing - Personal Name  (R)

401 - 409  unassigned

410  See From Tracing - Corporate Name  (R)

411  See From Tracing - Meeting Name  (R)

412 - 429  unassigned

430  See From Tracing - Uniform Title  (R)

431 - 446  unassigned

447  See From Tracing - Named Event  (R)

448  See From Tracing - Chronological Term  (R)

449  unassigned

450  See From Tracing - Topical Term  (R)

451  See From Tracing - Geographic Name  (R)

452 - 454  unassigned

455  See From Tracing - Genre/Form Term  (R)

456 - 461  unassigned

462  See From Tracing - Medium of Performance Term  (R)

463 - 479  unassigned

480  See From Tracing - General Subdivision  (R)

481  See From Tracing - Geographic Subdivision  (R)

482  See From Tracing - Chronological Subdivision  (R)

483 - 484  unassigned

485  See From Tracing - Form Subdivision  (R)

486 - 499  unassigned

See Also From Tracings:

500  See Also From Tracing - Personal Name  (R)

501 - 509  unassigned

510  See Also From Tracing - Corporate Name  (R)

511  See Also From Tracing - Meeting Name  (R)

512 - 529  unassigned

530  See Also From Tracing - Uniform Title  (R)

531 - 546  unassigned

547  See Also From Tracing - Named Event  (R)

548  See Also From Tracing - Chronological Term  (R)

549  unassigned

550  See Also From Tracing - Topical Term  (R)

551  See Also From Tracing - Geographic Name  (R)

552 - 554  unassigned

555  See Also From Tracing - Genre/Form Term  (R)

556 - 561  unassigned

562  See Also From Tracing - Medium of Performance Term  (R)

563 - 579  unassigned

580  See Also From Tracing - General Subdivision  (R)

581  See Also From Tracing - Geographic Subdivision  (R)

582  See Also From Tracing - Chronological Subdivision  (R)

583 - 584  unassigned

585  See Also From Tracing - Form Subdivision  (R)

586 - 599  unassigned

600 - 639  unassigned

Series Treatment:

640  Series Dates of Publication and/or Sequential Designation  (R)

641  Series Numbering Peculiarities  (R)

642  Series Numbering Example  (R)

643  Series Place and Publisher/Issuing Body  (R)

644  Series Analysis Practice  (R)

645  Series Tracing Practice  (R)

646  Series Classification Practice  (R)

647 - 649  unassigned

650 - 662  unassigned

Complex Name References:

663  Complex See Also Reference - Name  (NR)

664  Complex See Reference - Name  (NR)

665  History Reference  (NR)

666  General Explanatory Reference - Name  (NR)

Notes:

667  Nonpublic General Note  (R)

668  Note - Characters in Nonroman Alphabets  [obsolete]  [USMARC only]

669  unassigned

670  Source Data Found  (R)

671  Note - Work Catalogued (Names/Titles)  [obsolete]  [CAN/MARC only]

672  Title Related to the Entity  (R)

673  Title Not Related to the Entity  (R)

674  unassigned

675  Source Data Not Found  (NR)

676  Note - Cataloging Rules (Names/Titles)  [obsolete]  [CAN/MARC only]

677  Definition  (R)

678  Biographical or Historical Data  (R)

679  unassigned

680  Public General Note  (R)

681  Subject Example Tracing Note  (R)

682  Deleted Heading Information  (NR)

683 - 684  unassigned

685  Note - Source Data Found (Subjects)  [obsolete]  [CAN/MARC only]

686  Note - Source Data Not Found (Subjects)  [obsolete]  [CAN/MARC only]

687  Note - Usage (Subjects)  [obsolete]  [CAN/MARC only]

688  Application History Note  (R)

689 - 699  unassigned

Heading Linking Entries:

700  Established Heading Linking Entry - Personal Name  (R)

701 - 709  unassigned

710  Established Heading Linking Entry - Corporate Name  (R)

711  Established Heading Linking Entry - Meeting Name  (R)

712 - 729  unassigned

730  Established Heading Linking Entry - Uniform Title  (R)

731 - 746  unassigned

747  Established Heading Linking Entry - Named Event  (R)

748  Established Heading Linking Entry - Chronological Term  (R)

749  unassigned

750  Established Heading Linking Entry - Topical Term  (R)

751  Established Heading Linking Entry - Geographic Name  (R)

752 - 754  unassigned

755  Established Heading Linking Entry - Genre/Form Term  (R)

756 - 761  unassigned

762  Established Heading Linking Entry - Medium of Performance Term  (R)

763 - 779  unassigned

780  Subdivision Linking Entry - General Subdivision  (R)

781  Subdivision Linking Entry - Geographic Subdivision  (R)

782  Subdivision Linking Entry - Chronological Subdivision  (R)

783 - 784  unassigned

785  Subdivision Linking Entry - Form Subdivision  (R)

786 - 787  unassigned

788  Complex Linking Entry Data  (NR)

789 - 799  unassigned

Other Variable Fields:

800 - 855  unassigned

856  Electronic Location and Access  (R)

857 - 879  unassigned

880  Alternate Graphic Representation  (R)

881 - 882  unassigned

883  Metadata Provenance  (R)

884  Description Conversion Information  (R)

885  Matching Information  (R)

886 - 899  unassigned

Locally Defined Fields:

9XX  Local Implementation

9XX - Equivalent Headings  [obsolete, 1997]  [CAN/MARC only]

See also:

Variable Control Fields

Variable Data Fields

MARC 21 Format for Authority Data:  Contents