How do we identify Versions of an Abstract Dataset?

There are a lot of conversion:version_identifiers that look like "2010-Dec-09" and dataset URIs that have "version/2010-Dec-09". What does that date mean? Does it have to be a date? What methodology should a curator use to name the Version?
Now being maintained at
  • It is highly recommended to REUSE the source organization's name for the version.
  • Next, the Last Modified date as reported by the URLs should be used
  • Finally, today's date (i.e., date of retrieval) can be used.
  • Optionally, a curator's tag could be used (e.g., we used "mashathon" during a mashathon)
When using a date, use the form "2010-Dec-31" in "year-mon-day" form. This follows the "larger to smaller" convention of the URI decomposition. Also, "Dec" instead of "12" aids reading identifiers -- THEY ARE NOT INTENDED FOR PARSING, ONLY AS HUMAN AIDS. If date modeling is required, do so with appropriate RDF vocabularies and xsd:date formats elsewhere.