XSD licences?

[Markus Demleitner]

Dear GWS, dear TCG,

(GWS because you've traditionally been something like a steward of
our XML schema use)

I've got a problem in that I'm trying to get my DaCHS publication
package into Debian main and hence need to be clear on the licences
of the files I'm distributing.

And DaCHS really can hardly live without local copies of our XML
schemas; for instance, it validates registry records quite regularly,
and it'd suck if it had to hit ivoa.net ~ five times every time it
did that[1].

Hence, it would be great if we could agree on a licence for our XSDs.
Which gives rise to the next problem: The XSDs don't even have a
copyright holder.  I'm rather sure the holders of the copyright (in
the German jurisdiction: people who did non-trivial work on the
schema files) would happily transfer it to the IVOA (for what I've
written I would), but copyright transfers are a horror and don't even
work in my jurisdiction).

So... can we simply say that our schema files are distributed under
CC-0?  The cool thing is that we can do this without holding the
copyright; on the other hand, we'd of course have a problem if one of
the authors suddenly claimed their copyright and didn't agree with
the non-licence.  But again, I think it's fairly safe to assume that
won't happen.

To do the CC0 thing to an extent that I could hold my case against
the Debian ftpmasters (who suspiciously eye all the files they're
asked to distribute), I *think* it would be marginally enough to
have, as on the RDF repo (http://ivoa.net/rdf), a statement like

  IVOA XML schema files are made available under CC-0 by the IVOA
  Executive Committee [or someone else: the TCG?  the GWS WG?]. 

near the foot of https://ivoa.net/rdf/.  "CC-0" would href
http://creativecommons.org/publicdomain/zero/1.0/.

Once that's done, we could further and add and XML comments like

  <filename> – IVOA XML schema for X

  Written 2003-2020 by many authors within the IVOA community.

  This file is made available by the IVOA under the CC0
  Public Domain Dedication,
  http://creativecommons.org/publicdomain/zero/1.0/

to the individual files -- but that's a lot more work, in particular
because we would need to track down all the various sources of the
schema files, perhaps re-upload, and so on.  But as I said, I don't
think I really need that for the Debian upload.  So, I suppose that
could happen as the XSDs get reviewed over time.


So... can I have CC0 XSDs?  Pleeeaaaaase?

          -- Markus

[1] Where at least DaCHS wouldn't trigger the google analytics that
still hurt me every time I notice they're still on ivoa.net, so at
least it wouldn't be *that much* of a privacy issue.