Epubcheck has crafted an interesting approach to validating adobe page template declarations whereby you only have to have a manifest fallback if there isn't also a css style sheet declaration in the html file. It doesn't match any prose from the specification, however, and I'm not entirely sure it even makes a lot of sense to require a css declaration/fallback.

I don't know if page templates are used any more, but it got me wondering why we treat linked resources In xhtml docs as publication resources at all. We don't treat package linked resources that way.

Right now, we only exempt linked resources if rel="pronunciation" is specified, but is there any reason not to extend the same to all resources referenced from link?