There are two tag sets defined in the Z39.50 schema, tagSet-M and tagSet-G. TagSet-M includes elements designed to be used in a meta-data database, while tagSet-G has generically useful elements. Each element has a name and number, given here.
For a full definition of these tagsets, see http://lcweb.loc.gov/z3950/agency/defns/tag-gm.html
| Element | Number | Element | Number |
| schemaIdentifier | 1 | title | 1 |
| elementsOrdered | 2 | author | 2 |
| elementOrdering | 3 | publicationPlace | 3 |
| defaultTagType | 4 | publicationDate | 4 |
| defaultVariantSetId | 5 | documentId | 5 |
| defaultVariantSpec | 6 | abstract | 6 |
| processingInstructions | 7 | name | 7 |
| recordUsage | 8 | date | 8 |
| restriction | 9 | bodyOfDisplay | 9 |
| rank | 10 | organization | 10 |
| userMessage | 11 | postalAddress | 11 |
| url | 12 | networkAddress | 12 |
| record | 13 | eMailAddress | 13 |
| local control number | 14 | phoneNumber | 14 |
| creation date | 15 | faxNumber | 15 |
| dateOfLastModification | 16 | country | 16 |
| dateOfLastReview | 17 | description | 17 |
| score | 18 | time | 18 |
| wellKnown | 19 | DocumentContent | 19 |
| recordWrapper | 20 | language | 20 |
| defaultTagSetId | 21 | subject | 21 |
| languageOfRecord | 22 | resourceType | 22 |
| type | 23 | city | 23 |
| Scheme | 24 | stateOrProvince | 24 |
| costInfo | 25 | zipOrPostalCode | 25 |
| costFlag | 26 | cost | 26 |
| Record Created By | 27 | format | 27 |
| Record Modified By | 28 | identifier | 28 |
| rights | 29 | ||
| relation | 30 | ||
| publisher | 31 | ||
| contributor | 32 | ||
| source | 33 | ||
| coverage | 34 | ||
| private | 35 | ||
| databaseName | 36 | ||
| recordId | 37 | ||