This attribute is used with two different definitions:
- The most common is to name the thesaurus, ontology, or
organization that established a particular group of keywords, for example, “
MESH
”,
“
ISO-463
”,
“
IEEE
”,
“
author-generated
”,
“
ICD9-codes
”, etc.
- The second usage describes the type of keyword,
for some of the more unusual keyword groups (for
example, “
hierarchical
”
for keywords that
are grouped into a hierarchy,
“
abbreviations
” for
keywords that contain an abbreviation and its expansion,
or “
code
” for
keywords that contain a code
and its text but where the source of the codes is unknown).
| Value |
Meaning |
| Text, numbers, or special characters |
The source of keywords. This may be an organization (such as “
IEEE
”) or the name of a thesaurus, subject index, or ontology (such as “
MESH
”).
|
| Restriction: This attribute may be specified if the element is used.
|