- From: Glenn A. Adams <glenn@xfsi.com>
- Date: Sun, 16 Feb 2003 13:47:13 -0500
- To: "Ian B. Jacobs" <ij@w3.org>
- Cc: <www-tag@w3.org>
>Message-ID: <3E399D11.5060102@w3.org> >Date: Thu, 30 Jan 2003 16:45:53 -0500 >From: "Ian B. Jacobs" <ij@w3.org> >To: Liam Quin <liam@w3.org> >CC: Paul Grosso <pgrosso@arbortext.com>, www-tag@w3.org, Michael Sperberg-McQueen <cmsmcq@w3.org> >Subject: [xmlProfiles-29] TAG recommendation for work on subset of XML 1.1 >One clear requirement of the subset is that it must exclude >internal and external subsets (no <!DOCTYPE declaration is >allowed). This requirement effectively removes DTDs from XML and >consequently removes entities and notations. I want to point out the existence of a number of standards in the television domain that: (1) disallow internal declaration subsets; (2) require standalone="no"; (3) require a document type declaration, with a specifically enumerated set of public FPIs to be supported; These standards include: (1) ATSC DTV Application Software Environment (DASE) [1] (2) DVB Multimedia Home Processing (MHP) Version 1.1 [2] (3) SMPTE 363M Declarative Data Essence Level 1 [3] The rationale for the restrictions adopted by these standards include: * inability to request external entities in a broadcast only transport environment coupled with inadequate bandwidth for broadcast of DTDs; * unacceptable complexity in mandating DTD declaration parsing document validation in small footprint, embedded devices (set-top boxes and integrated receiver decoder devices); * need to support specific, limited set of document types; while allowing (but not requiring) validation based on pre-compiled DTDs; * need to identify content as to specific document type against which optional validation and application specific processing may occur; As a result of this usage, I would have to conclude that complete elimination of document type declaration is overkill, as it removes valuable (FPI) information requiredby these standards and the systems which employ them. Regards, Glenn Adams [1] http://www.atsc.org/standards/ps_documents/PS-100-2.pdf [2] http://pda.etsi.org/pda/home.asp?wki_id=13397 [3] http://www.smpte.org/shopping_cart/cart.cfm?function=add&productid=1481
Received on Sunday, 16 February 2003 13:47:18 UTC