[imsc] `ittp:activeArea` extent wording

spoeschel has just created a new issue for https://github.com/w3c/imsc:

== `ittp:activeArea` extent wording ==
[§6.7.5 in IMSC 1.0.1](https://www.w3.org/TR/ttml-imsc1.0.1/#ittp-activeArea) currently contains the following wording:

    The Active Area SHALL NOT extend outside the root container in any dimension.

However, as a consequence of the changes to the value syntax definition discussed/applied in #211, it is no longer possible to specify a `ittp:activeArea` value that is syntactically valid and nevertheless extends beyond the root container. So the mentioned wording is a redundancy to me (compared to the value syntax definition) and also quite confusing: It could be read as if that case - value syntactically correct, but semantically wrong - could happen and hence an implementer had to consider it.

So I would prefer to remove this wording and rather replace it by adding a NOTE to the value syntax definiton like the following:

    By definition the Active Area cannot extend outside the root container in any dimension.

Please view or discuss this issue at https://github.com/w3c/imsc/issues/288 using your GitHub account

Received on Wednesday, 10 January 2018 07:59:00 UTC