Changing 1.0 functionality

[Lofton Henderson <lofton@rockynet.com>]

Having looked at some of Chris's comments, I am concerned about one
aspect.  Some of his comments effectively are asking for changes to
1.0 functionality.  We will see more of this, coming from I18N and
WAI.  

Some of our responses may involve (in part), "that is standardized
1.0 functionality, and changing it should be considered beyond the scope
of 2.0."  I.e., forward compatibility and continuity are strong
criteria, unless there are pretty good reasons to deviate.

That cannot be a blanket policy, but I think we (CGMO) need to be
extremely careful about initiating changes to 1.0 stuff on our own,
unless the reasons are really compelling.  (And even then, WAI and
I18N may consider their reasons compelling.)  If we're not careful,
we could end up opening and arguing issues, and getting to REC much later
than the already draft WG Charter projection.

Here are three examples, for purposes of illustration:

1.) Safe.  we removed the 'viewport' PARAM.  This might be
considered "safe" -- a simple functionality that no one
implemented in 5 years.  (W3C allows specs to drop functionality at
CR stage, if it's unimplemented).

2.) Unsafe.  I consider the object behaviors mapping issue to be
"unsafe" -- while we might be able to convincingly justify the
change in how 2.0 viewers handle view_context ("it was broken in
1.0, doesn't map into the new 2.0 behaviors set, etc"), I think we
would establish a regrettable precedent if we changed how 'highlight' and
'highlight_all' behave in 2.0 viewers (because the 1.0 behavior was
clearly defined, implemented, and maps simply to a 2.0 equivalent):
http://www.oasis-open.org/apps/org/workgroup/cgmo-webcgm/email/archives/200603/msg00023.html

3.) Inbetween/indeterminate.  Benoit's recent presentation of
compositing model issues presents a more complex (and less obvious)
case.  My point in mentioning it, and the point of this message
(again), is that I want to measure any changes to the listed
functionality (all 1.0 stuff) against a "really compelling"
criterion (and honestly, I haven't yet digested all of his excellent
analysis, nor formed an opinion):
http://lists.oasis-open.org/archives/cgmo-webcgm/200604/msg00010.html

Regards,
-Lofton.