SSLDM status?

[Markus Demleitner]

Hi Gregory,

On Fri, Jul 10, 2026 at 10:35:09PM +0000, Dubois-Felsmann, Gregory P. via dm wrote:
> We would like to work with the relevant IVOA standards, so we've
> been looking at SSLDM in particular.  We see that there's a pending
> SSLDM v2.0 RFC that is marked as "frozen" pending work on an SLAP
> v2.0. =

I guess I'm a least partly responsible for that "frozen" status.  You
see, there is a well-established, if somewhat complex, data model for
line data, produced by VAMDC <https://vamdc.org/> (shorthand: XSAMS,
even if that's a serialisation and not really the model).  XSAMS,
admittedly, is fairly complex, presumably more complex than it would
be if we in astronomy did a custom job.

On the other hand, even that custom job (i.e., SSLDM) is already so
complex that we'd not be saving much (but investing a lot) if we
built it.  Hence, in SLAP2 we're building on top of VAMDC, and I
think whatever other work on structured representation of lines is
being done should make a similar choice.

Whether your "line groups" are a case for the model or rather some
structure on top of it (like project-specific SLAP2 services perhaps,
or just XSAMS instances being handed around) I can't say; I'm not
part of VAMDC [which is a disclaimer I wanted to make anyway].

Thanks,

         Markus