ISO-Specific Project Identifier
The project number for the project within which this standards document was developed.
Different Metadata Levels: The <proj-id> element may be used directly inside <std-meta> or within <doc-ident> (which is inside the three ISO-related standards metadata elements: <iso-meta>, <reg-meta>, and <nat-meta>).
ISO Note: For ISO-related Processing, this element holds an ISO or ISO associate’s project number. In ISO STS, from which this Tag Set was developed, a <proj-id> element was required in the metadata, but the ISO STS documentation states that authors/adopters would not always be able to provide this identifier. Therefore, software that processes the ISO-specific STS vocabulary (in both NISO STS and ISO STS) needs to be prepared for the empty string as content of this element.
Text, numbers, or special characters, zero or more
... <doc-ident> <sdo>ISO</sdo> <proj-id>57385</proj-id> <language>en</language> <release-version>IS</release-version> <urn>iso:std:iso-iec:guide:71:ed-2:v1:en</urn> </doc-ident> ...