SOSO Time of resource modification violations

[iannesbitt]

The following repositories are in violation of the SOSO Time of resource modification guidelines and should be contacted to change their configuration:

• NSIDC (does not have lastmod tags): https://nsidc.org/sitemap.xml
• Borealis (lastmod tags actually refer to the initial upload date, see this record for example https://borealisdata.ca/dataverse/strong): https://borealisdata.ca/sitemap.xml
• NPDC (lastmod tags may refer to initial publication date; need more info): https://npdc.nl/sitemap.xml
• OpenTopography (it's possible that the OpenTopo lastmod refers to the upload date rather than the date the dataset is made public. Need more in-depth investigation): https://portal.opentopography.org/sitemap.xml