In element <index-term-range-end>, this attribute must be used if the element is used.
| Value |
Meaning |
| An identifier (IDREF) |
Must point to an existing identifier within the standards document. |
In elements <milestone-end>, <milestone-start>, <nav-pointer>, and <related-term>, this attribute may be used if the element is used.
| Value |
Meaning |
| An identifier (IDREF) |
Points to the existing identifier within the standards document. |
In elements <aff>, <award-id>, <back>, <bio>, <contrib>, <def>, <editing-instruction>, <funding-source>, <named-content>, <see>, <see-also>, <see-also-entry>, <see-entry>, <sig>, <sig-block>, <term>, and <xref>, this attribute may be used if the element is used.
| Value |
Meaning |
| One or more identifiers (IDREFS) |
Points to one or more existing identifiers within the standards document. |