8xx the essential 8XX fields commonly used in MARC21 records with their respective indicators, subfields, descriptions, and examples: 800 - Series Added Entry-Personal Name : Indicators : Indicator 1 specifies whether the personal name is established in the Library of Congress Name Authority File (value "0") or not established (value "1"). Subfield $a : Personal name (Example: Rowling, J.K.) Subfield $b : Numeration (Example: III) Subfield $c : Titles and other words associated with a name (Example: Sir) 810 - Series Added Entry-Corporate Name : Indicators : Indicator 1 specifies whether the corporate name is established in the Library of Congress Name Authority File (value "0") or not established (value "1"). Subfield $a : Corporate name (Example: Library of Congress) Subfield $b : Subordinate unit (Example: Cataloging Policy and Support Office) 811 - Series Added Entry-Meeting Name : Indicators : Indicator 1 specifies whether the meeting name is established in the Library of Congress Name Authority File (value "0") or not established (value "1"). Subfield $a : Meeting name (Example: International Conference on Machine Learning) Subfield $n : Numbering (Example: 28th) Subfield $d : Date of meeting (Example: 2021) Subfield $c : Location of meeting (Example: New York, N.Y.) 830 - Series Added Entry-Uniform Title : Indicators : Indicator 1 specifies whether the uniform title is established in the Library of Congress Name Authority File (value "0") or not established (value "1"). Subfield $a : Uniform title (Example: Bible. New Testament. Greek) 841 - Holdings Coded Data Values : Indicators : Both indicators are typically undefined or contain blank values. Subfield $a : Holdings code (Example: 12345) Subfield $b : Summary holdings (Example: Vol. 1-10) 856 - Electronic Location and Access : Indicators : Indicator 1 specifies whether the electronic resource is available (value "4") or not available (value "8"). Subfield $u : Uniform Resource Identifier (Example: http://www.example.com ) Subfield $z : Public note (Example: Access may be restricted) 880 - Alternate Graphic Representation : Indicators : Both indicators are typically undefined or contain blank values. Subfield $6 : Linkage (Example: 880-01) Subfield $a : Alternate graphic representation (Example: 珠玉在侧)