The Issue

While investigating an issue with astropy.io.votable, I noticed that the wrong version of the VOUnits standard was being referenced in the discussion. Looking into it I found that the VOUnits reference in the VOTable standard Reference section was not pointing to the correct version of the standard. The VOUnits reference ( http://www.ivoa.net/documents/latest/VOUnits.html ) lands on an old PR for VOUnits instead of the more recent REC version.

I also noticed that the VOTable standard Reference section uses two difference forms of shortcut URL:

URL Form 1: https://ivoa.net/documents/latest/[std].html - Meant to point to the latest REC of the standard?

URL Form 2: https://ivoa.net/documents/[std] - Meant to point to the latest REC unless changes are in progress, in which case it would point to the most recent PR or WD?

Questions

• Are the above interpretations of form 1 and form 2 correct (i.e. form 1 is latest REC and form 2 is latest REC, WD or PR)?

• Are these shortcuts officially supported and/or reliable?
  • See table for results of trying both URL forms on all standards.
  • Form 1 seems much less reliable, making me wonder whether it's intended to be supported
  • If we fix form 1 links, do we need to fix all of them?

• How should standards documents be referencing other standards docs?
  • Is there a convention for this?
  • Should it vary depending on the use of the remote standard?
  • Examples:
    • Shortcut URLs like forms 1 and 2 above to get to some notion of "latest"
    • Direct URL to specific doc version
      • ivoa.net link or DOI link?

Trying the URLs

The table below shows the results of trying these two forms of document URL shortcuts for each standard. The results are very inconsistent for form 1 ( documents/latest/[std].html), but more solid for form 2 ( documents/[std]).

Table