VOEvent References

[Norman Gray]

Rick, hello.

On 2011 Mar 21, at 08:44, Frederic V. Hessman wrote:

>> By the way, should we be talking about this on both the Semantics and VOEvent lists?  I'd suggest limiting it to just the VOEvent list.
> 
> As alwas, VOEvent is leading the way in trying to incorporate semantic content, so why not?

I'd guess that most interested Semantics folk are on the VOEvent list, too, but I'll leave it as it is.

>>> 	- "type" gives the VO "mime" content description in a (soon to be?) standard VO format.
>> 
>> If it's a MIME type, then why not call it a MIME type?
> 
> Isn't the problem with MIME that it covers things like URI, HTML, JPEG but not other astronomical stuff (e.g. FITS).  Is there a SKOS vocabulary of MIME tags?  If so, then the standard stuff is easily covered (once everyone knows about it).

There isn't such a vocabulary of MIME types, but there _is_ a MIME type for FITS (RFC 4047 <http://www.rfc-editor.org/rfc/rfc4047.txt>), so that FITS and VOTable are both covered here (even though the VOTable type is still un-registered).

> My idea was to have as few tags as possible and force them to have controlled content (even if one chooses to ignore the possibility of checking).  All we need is
> 	- format (or "contentformat") : what bytes are at the end of the link
> 	- meaning (or "content") : what do the bytes really mean astronomically?

I think we're covered here.  I take your later remarks to be agreeing that the combination of MIME type and vocabulary type address these two goals.

>> The vocabulary term in the @contenttype attribute tells you what sort of information is at the end of the @uri, but gives no clues about what format it's in.  The MIME type in the @type attribute, and more authoritatively the content-type in the retrieval of the URI, tells you what syntactic format the URI-content has, but gives no clues about what it means.
>> 
>> They're orthogonal and complete.  Job done.
> 
> (champagne cork!)


On reflection, I think that @sciencetype (for the meaning of the information) and @mimetype (for the format) might be better attribute names.

Best wishes,

Norman


-- 
Norman Gray  :  http://nxg.me.uk
School of Physics and Astronomy, University of Glasgow, UK