`id` or `xml:id` (was `xml:id` should be used in example 6)

[iherman]

The content model section refers to xml:id as the base for identification, but Example 6 uses id. That should be changed for xml:id.

(I may have missed other examples where the same problem occurs.)

[iherman]

Note, however, that the EPUB media overlay uses id and not xml:id. Another alternative is to use id for out document, and forget about xml:id. That would mean to be compatible with the EPUB media overlay spec.

Note: the latest SMIL version deprecates the id element in favor of xml:id. "Deprecation" does not mean that it is invalid to use id. This means that:

• if we use xml:id then we are perfect SMIL 3 citizens but are incompatible with EPUB 3
• if we define and use id then we are not perfect SMIL 3 citizens but are compatible with EPUB 3

I.e., we cannot please both :-) Personally, I favor being compatible with EPUB 3, ie, to introduce id and drop the reference to xml:id.

[marisademeglio]

Good point, when I officially set the SyncMedia serialization format to XML, I was just trying to be a good citizen and do what other people did in their specs. I saw in TTML and SMIL that xml:id was used, rather than id. However, I am happy to just use id, to be more consistent with EPUB 3.