Proposed fix for DR 10-0016 ("MCE: Core Concepts")

Chris Rae Chris.Rae at
Tue Jul 6 20:21:27 CEST 2010

Hi guys - I think that we're probably all on the same page with regard to subsumption. Its functionality is already covered by other mechanisms, and it's hard to implement as written.

I see Alex's point (re. steering clear of normative provisions which rely on "meaning"). I wonder if we could say that applications can either add attributes in new namespaces to existing elements, or create entire elements in new namespaces, but then give an informative note saying it's a good idea not to create the entire element again unless its meaning has changed?

If there's general agreement that subsumption should be removed from the standard, I can submit a defect report through Ecma to have it removed.


-----Original Message-----
From: Jesper Lund Stocholm [mailto:jesper.stocholm at] 
Sent: 01 July 2010 00:21
To: Alex Brown; Chris Rae; e-SC34-WG4 at
Subject: RE: Proposed fix for DR 10-0016 ("MCE: Core Concepts")

Hi all,

> -----Original Message-----
> From: Alex Brown [mailto:alexb at]
> Sent: 1. juli 2010 08:38
> To: Chris Rae; e-SC34-WG4 at
> Cc: Jesper Lund Stocholm
> Subject: RE: Proposed fix for DR 10-0016 ("MCE: Core Concepts")

> Removing subsumption has the advantage of allowing us to erase a lot
> this cruft and will result in a smaller text.
> The way I see it, alternative content is markup for which "all bets
> off" anyway (except that the MCE Namespace is not used in content). I 
> think subsumption is conceptually and technically problematic, and 
> doesn't actually help implementers if (on top of that) it is optional 
> anyway.
> Or do any experts think "subsumption" is useful concept?

I think it makes a lot of sense to tighten up the text and make it more clear. I completely agree with you that when using MCE, "all bets are off". The problem with subsumption is that is kind of indicates that it makes stuff "a little bit easier". However, I seriously question that - not only from a point of view of understanding the concept itself - but also when implementing explicit support for subsumed/ing namespaces.

Med venlig hilsen / Best regards

Jesper Lund Stocholm

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