To be able to discover previous versions of a document automatically from a document.
- W3C. Nearly every W3C specification has a link in the header to the "Previous Version".
revision control systems
Revision control systems (RCS) like:
- mercurial (hg)
All have ways of representing previous versions of a document.
Several rel values are being considered for linking from a document to a previous version of that document.
- -1 Tantek: "older" feels wrong as a noun.
A related use case is to be able to find the current version of document when looking at an older version. For this, the following rel values are being considered:
You can already use:
- rel-canonical to link to the canonical version of a page. But this doesn't mean it's a different version, if anything, it may be the exact same content just at a shorter or more reliable/official URL.