[tei-council] tricky situations for using @validUntil

[Sebastian Rahtz]

On 11 Dec 2013, at 03:36, Syd Bauman <s.bauman at NEU.EDU> wrote:
> I have to admit, I think I'm mildly partial to either @errorAfter as
> an attribute or perhaps a PI. As an attribute it is just a flag to us
> to make us change something before building works. That might make
> sense in places where @validUntil doesn't make sense. However, it
> might be better to use a PI, in that one can then
> a) put the flag pretty much anywhere, and 
> b) store additional helpful info. E.g.
>     <?tei-council fatalDate 2017-12-01 featureRequest 812 
>                   sometime before the 2018 Q1 build this class
>                   should be renamed to "foo-bar". ?>

i have a mild antipathy to PIs; partly because they smack of undocumented magic,
and partly because they are so seldom used by anyone these days. Both these things bother
me because they raise the barrier to new people editing the Guidelines over time,
and adoption of ODD by non-TEI people. 

I’m fairly attracted by your #1, viz use @validUntil on a constrainSpec, so that
the constraint is ignored until that date, but is then added to the schema.

Sebastian