[VEP-0002] DataLink semantics vocabulary enhacement proposal = new DataDocumentation term

[Carlos Rodrigo]

> I'm still not quite sure what this might be -- perhaps a concrete
> example would help?  Plus: If you had to tell Mark Taylor what TOPCAT
> should suggest as an action with such a link, what would it be?
> Under which circumstances should it show up, more generally, in a
> links menu of a sufficiently sophisticated client?

Provide the URL in the list of resources telling the user that this is a link to documentation

Other applications could provide a clickable link to the actual URL that could be opened in a
browser (I don't think that this fits in TOPCAT)

Some examples:

http://svo2.cab.inta-csic.es/vocats/v2/ltsa/dl.php?ID=SDSS_J12181286%2B0706104
http://svo2.cab.inta-csic.es/vocats/v2/ltsa/dl.php?ID=LHS_2419
http://svo2.cab.inta-csic.es/vocats/gbs3/dl.php?ID=ESPaDOnS_tauCet-1

You can also see

http://svo2.cab.inta-csic.es/vocats/v2/ltsa/index.php?action=search&nocoor=1&VERB=3&boton=Search&nlist=1&good=1&nres=all

with a web representation of the first catalogue, which you can see as an "application".
When you click on any of the "Links" link you see a visual representation of the corresponding
dataLink content (in the way that I have wished to implement it). Some of the links just make you
download something, while other links (like the ADS references) just open in another browser window.

Carlos