- From: Dan Connolly <connolly@w3.org>
- Date: Fri, 23 Jan 2009 11:11:36 -0600
- To: Lachlan Hunt <lachlan.hunt@lachy.id.au>
- Cc: public-html@w3.org, Sam Ruby <rubys@us.ibm.com>
On Fri, 2009-01-16 at 16:03 +0100, Lachlan Hunt wrote: > Henri Sivonen wrote: > > <!DOCTYPE html SYSTEM "about:sgml-compat"> would seem to fit the > > requirements as a legacy generator alternative to <!DOCTYPE html>. > > Based on some further discussion in IRC, these are the advantages of > using the SYSTEM identifier with an about: URI scheme. > > * Many people are already familiar with the scheme and so it's > memorable. More so than, e.g., the tag: or data: URI schemes. I certainly prefer it to system identifiers that aren't absolute URIs. Meanwhile, about: is not registered; it probably should be. http://www.iana.org/assignments/uri-schemes.html The best reference for it that I know of is Client-Side JavaScript Reference http://developer.netscape.com/docs/manuals/js/client/jsref/index.htm The ESW wiki has a pretty good list of URI schemes http://esw.w3.org/topic/UriSchemes including http://esw.w3.org/topic/UriSchemes/about Though wikipdia's is perhaps even better; about: is listed under "Unofficial but common URI schemes" http://en.wikipedia.org/wiki/URI_scheme#Unofficial_but_common_URI_schemes I sure hope IETF/IANA registry practice starts to feel more like wikipedia sometime soon. > * It's shorter than an equivalent http: URI would be > > * It's non-retrievable and so there's no expectation of a DTD. > > * Use of an absolute URI rather than a string like "sgml-compat" that is > indistinguishable from a relative URI prevents consumers that attempt > to retrieve DTDs from getting 404s from many servers. > > * Typing about:sgml-compat into browsers generally results in an error > message or blank page. This helps in pre-empting any bogus > rationalisations for why using this one with the URI is better than > <!DOCTYPE html> without the URI. > > * As Philip demonstrated earlier, using a SYSTEM identifer is generally > more compatible with legacy producers than a lone PUBLIC identifier. > -- Dan Connolly, W3C http://www.w3.org/People/Connolly/ gpg D3C2 887B 0F92 6005 C541 0875 0F91 96DE 6E52 C29E
Received on Friday, 23 January 2009 17:13:04 UTC