- From: Martin J. Dürst <duerst@it.aoyama.ac.jp>
- Date: Mon, 29 Aug 2011 09:51:21 +0900
- To: Jonathan Rees <jar@creativecommons.org>
- CC: www-tag@w3.org, Manu Sporny <msporny@digitalbazaar.com>, Harry Halpin <hhalpin@ibiblio.org>, Ian Davis <me@iandavis.com>
Hello Jonathan, On 2011/08/29 2:27, Jonathan Rees wrote: > Question to the broader www-tag readership (and beyond): > > I don't want to start another argument, I just want to understand the > position that it is necessary to use absolute (i.e. hashless) URIs > instead of hash URIs for semantic web / linked data purposes, and > record the reasons for this position somewhere. I attempted this in > http://www.w3.org/2001/tag/awwsw/issue57/20110625/#hash but I feel > the case I made against # URIs there is not convincing. > > That is, suppose you want a URI to use in RDF as a reference (name, > "identifier", whatever) for something other than the web page > (document, "information resource", whatever) at that URI. Why is it so > important that the URI be absolute, instead of one containing # ? Just some comment on terminology: While RFC 3986 uses the ABNF production <absolute-URI> for an absolute URI without fragment identifier, the adjective 'absolute' in connection with 'URI', contrary to what your text might suggest, does not imply that there is no '#', only that it starts with a scheme and can therefore be resolved independent of any 'base' URI. So while http://www.w3.org/2001/tag/awwsw/issue57/20110625/#hash, for example, is not an <absolute-URI>, it is nevertheless an absolute URI (because it is independent of the context of a base URI). For details, please see http://tools.ietf.org/html/rfc3986#section-4.3, http://tools.ietf.org/html/rfc3986#section-5.1, and http://tools.ietf.org/html/rfc3986#appendix-D.1, where the "without fragment identifier" qualification is always present if necessary. That the <absolute-URI> production has the name it does seems to come from the fact that in a predecessor of RFC 3986, the '#' sign and the fragment syntax were treated specially. Also, as far as I understand, the actual distinction between absolute and relative is largely irrelevant for your question; relative URIs would just be used for convenience where they are possible because they are shorter, but the choice of a relative (where possible) or an absolute URI wouldn't affect the discussion. So please go through your text and fix occurrences of 'absolute' where they are supposed to mean 'hashless'. Just using 'hashless' or 'without fragment identifier' should be fine, but if there are cases where you have problems with the wording, please feel free to ask for text suggestions. Regards, Martin.
Received on Monday, 29 August 2011 00:52:15 UTC