| Code | Display | Definition | 
| abstract  | 
Abstract | 
The URL will reach a brief summary for the article. | 
| full-text  | 
Full-Text | 
The URL will reach the full-text of the article. | 
| supplement  | 
Supplement | 
The URL will reach a supplement, appendix, or additional supporting information for the article. | 
| webpage  | 
Webpage | 
The URL will reach a webpage related to the article, where the content is not easily classified as abstract, full-text or supplement. | 
| file-directory  | 
File directory | 
The URL will reach a file directory. | 
| code-repository  | 
Code repository | 
File archive and web hosting facility for source code of software, documentation, web pages, and other works. | 
| restricted  | 
Restricted | 
The URL content has restricted access (e.g. subcription required). | 
| compressed-file  | 
Compressed file | 
Compressed archive file (e.g. a zip file) that contains multiple files | 
| doi-based  | 
DOI Based | 
The URL is derived from the Digital Object Identifier (DOI). | 
| pdf  | 
PDF | 
The URL will reach content in PDF form. | 
| json  | 
JSON | 
The URL will reach content in JSON format. | 
| xml  | 
XML | 
The URL will reach content in XML format. | 
| version-specific  | 
Version Specific | 
The URL will reach content that is a specific version of the article. | 
| computable-resource  | 
Computable resource | 
The URL will reach content that is machine-interpretable. | 
| not-specified  | 
Not Specified | 
Used when URL classifier is not specified but expected in a system. |