SCS2: POS plus RA/DEC/SR

[Markus Demleitner]

Dear DAL folks,

On Mon, Sep 14, 2026 at 04:09:37PM -0700, Patrick Dowler via dal wrote:
> A circle parameter would have a defined (DALI) xtype and value
> serialisation and be required for SCSv2; other such params (POLYGON,
> MOC, etc) could be defined now or later and be optional. Then it comes
> down to declaring which parameter names are supported (capabilities or
> service descriptors) rather than which variants of POS are supported.

As I had said, I like Pat's idea, and thus I've made
<https://github.com/ivoa-std/SCS2/pull/9>.  This

* Drops POS and introduces CIRCLE
* Makes CIRCLE support mandatory (less optional=more happiness)
* Allows the repetition of CIRCLE
* But allows clients to reject more than n CIRCLEs
* And let them declare how many CIRCLEs they are prepared to accept
  in the capability extension (thus pushing the schema version to
  1.2)
* And since we can do multicone in this way, I drop UPLOAD support.

What does everyone think?  Please review (and please review the
remaining PRs, too)...

Thanks,

      Markus