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Solution with datalink seems OK: detached labels provided under datalink_url in a table - although no attempt made to read them from the portal, yet (use VIR unpublished service to test this).
• Utypes
Need to clean up current doc (2.0). Utypes are = DM fields. They are supposedly used to identify the meaning of parameters and help e.g. tools to grab required quantities - This will not work in some areas though, e. g. with spectral tools as they currently use UCD instead of Utype for this purpose (not many tools appear to actually rely on Utype in fact). See discussion here for usage (a bit old?): http://www.ivoa.net/documents/Notes/UTypesUsage/20130213/NOTE-utypes-usage-1.0-20130213.html
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