Normatizing the fixed layout property statements

[wareid]

The Fixed Layout properties section of the RS spec makes a number of informative default statements for the various rendition properties, but only one of them is a normative statement.

The default value reflowable MUST be assumed by EPUB Reading Systems as the global value if no meta element carrying this property occurs in the metadata section section [EPUB-33].

The default value statements for rendition:orientation and rendition:spread are both informative (and the same).

The default global value is auto if no meta element carrying this property occurs in the metadata section.

I would propose making these both normative MUST statements to match the statement made for rendition:layout and to clarify this section.

[mattgarrish]

Earlier in the revision we changed from Reading Systems must support the default value to the current prose without a normative keyword because it was said the statements weren't useful for auto values: #1313

The assertion cannot be failed, but that was always by design to allow the default behaviour of reading systems to pass.

Are we okay with testing auto again?

[iherman]

The issue was discussed in a meeting on 2021-12-09

List of resolutions:

• Resolution No. 2: Elevate the default behaviour statements for rendition:orientation and rendition:spread to MUSTs.

View the transcript

3. Normatizing the fixed layout property statements (issue epub-specs#1936)

See github issue epub-specs#1936.

Wendy Reid: i noticed that in RS spec we say in rendition:layout that the default value is a MUST.
… but for the other 2 FXL properties even though we also define default behaviour, we don't make those statements normative.

Dave Cramer: there are a couple instances where we say that the default value MUST be assumed, but i didn't know how that would be testable.

Wendy Reid: the default behaviour is auto, and that means to respect what the RS is doing.
… so the test would pass if the epub appears in way that would respect the app settings or the user settings.
… which is essentially what auto is meant to do.

Brady Duga: you could not specify in one case and specify in another case, and if the result is the same then the RS passes?.

Wendy Reid: my proposal was to turn the 2x non-normative default behaviour statements into normative MUSTs.
… i've already made the tests for both of them.

Dave Cramer: so we just ask mgarrish to made the change, then.

Proposed resolution: Elevate the default behaviour statements for rendition:orientation and rendition:spread to MUSTs. (Wendy Reid)

Brady Duga: +1.

Shinya Takami (高見真也): +1.

Wendy Reid: +1.

John Roque: +1.

Matthew Chan: +1.

Toshiaki Koike: +1.

Theresa O'Connor: +1.

Murata Makoto: +1.

Dave Cramer: +1.

Masakazu Kitahara: +1.

Resolution #2: Elevate the default behaviour statements for rendition:orientation and rendition:spread to MUSTs.