[css3-regions] issue: is first region initial containing block

Discussion on stacking context morphed into a discussion on positioning in regions and in pages.

http://lists.w3.org/Archives/Public/www-style/2012Feb/0136.html

Absolute positioning in fragmented flow in general should be defined outside regions spec (css3-fragmentation I would assume).

Whether or not first region is ICB for named flow content (and therefore positioned content is constrained to regions) or not - that deserves a separate decision, which to me seems related to stacking context decision.

I think we should have an issue for the spec and discuss it together with stacking.

My opinion: if stacking context for region is to be made optional (especially to allow matching stacking behavior of columns), constraining of positioning to regions will have to be optional for the same reason.