Matt Garrish

> Moreover, I think "a reading system MUST NOT resolve [external identifiers](https://www.w3.org/TR/xml/#NT-ExternalID) in DOCTYPE, ENTITY and NOTATION declarations" is just harmful and has no advantages. Isn't this standard practice for...

> Resolving external entities is one of them, but internal entities can be used to cause more serious problems. Yes, but we don't restrict internal entities in the authoring spec....

I'm a bit concerned that we're blurring the lines of conformance with this change. I understand where you're trying to go with the paragraph, but couldn't we do it in...

> we define, "normatively", so to say, the conformance of a RS in the first paragraph, and then we would slightly weaken it in the note I don't know that...

> For instance, does this mean if you support side loading you can't reject due to epub check (or other) errors? This is where I thought the original issue was...

I think we're worrying too much about making reading systems in closed loops conformant. I'd be fine leaving that part unstated and let those vendors it affects explain why they...

I'd still like to drop the formal exception and only make a note if we can. Could we link in "distributed system" here to explain that requirements can be satisfied...

> * The syntax of this grammar is also influenced by the parsing algorithm for the `viewport` `meta` element, as defined in [css-device-adapt](https://www.w3.org/TR/epub-33/#bib-css-device-adapt). This is certainly doable. We can also...

> if you're confident that the normative syntax restriction cannot hit us back, then I'm OK For me, the requirement for reading systems to ignore the tag makes any concerns...

> I guess the reason is that this is probably not widely implemented... It was only added this revision. Given that a reading system could opt to not display the...