(2014-07-31) Bernard Vatant: The version date is taken from the HTML documentation. The changing values of dcterms:modified in the RDF files trigger false positive in version history. This issue is under investigation by the vocabulary publisher. See https://github.com/GSA/data.gov/issues/407.
(2015-07-19) Ghislain Atemezing: Added homepage as indicated in the machine readable format. However, there is still an issue between the last update field in the HTML file and the RDF files.