| Code | Display | Definition |
| publication-type | Publication type | Publication type |
| mesh-heading | MeSH heading | MeSH heading |
| supplemental-mesh-protocol | Supplemental MeSH for Protocol | Supplemental MeSH for Protocol |
| supplemental-mesh-disease | Supplemental MeSH for Disease | Supplemental MeSH for Disease |
| supplemental-mesh-organism | Supplemental MeSH for Organism | Supplemental MeSH for Organism |
| keyword | Keyword | Keyword |
| citation-subset | Citation subset | Citation subset |
| chemical | Chemical | Chemical |
| publishing-model | Publishing Model | Used for PubModel attribute in Medline |
| knowledge-artifact-type | Knowledge Artifact Type | Knowledge Artifact Type |
| coverage | Coverage | The spatial or temporal topic of the resource, spatial applicability of the resource, or jurisdiction under which the resource is relevant |