Next message: Jukka Korpela: "Re: Suggestion for Change in HTML Validatior"
Message-Id: <v03130300b67f28c58485@[134.226.35.13]>
Date: Mon, 8 Jan 2001 08:22:38 +0000
To: www-validator@w3.org
From: David M Abrahamson <david.abrahamson@cs.tcd.ie>
Subject: Suggestion for Change in HTML Validatior
Hello there,
I have recently come across a commercial web site that uses HREFs of the
form <A HREF="url:http://www.xyz.com">. While Internet Explorer is capable
of following such links, Netscape is not, but when I suggested to the web
owner that his page was broken, he informed me that it validates okay.
Quoting from RFC 2396 "Uniform Resource Identifiers (URI): Generic Syntax"
- Berners-Lee, et al, August 1998:
3. URI Syntactic Components
The URI syntax is dependent upon the scheme. In general, absolute
URI are written as follows:
<scheme>:<scheme-specific-part>
An absolute URI contains the name of the scheme being used (<scheme>)
followed by a colon (":") and then a string (the <scheme-specific-
part>) whose interpretation depends on the scheme.
This requires that "url:http" be a valid scheme, which it is not.
Once again, quoting from RFC 2396:
E. Recommendations for Delimiting URI in Context
...
In practice, URI are delimited in a variety of ways, but usually
within double-quotes "http://test.com/", angle brackets
<http://test.com/>, or just using whitespace ...
These wrappers do not form part of the URI.
...
For robustness, software that accepts user-typed URI should attempt
to recognize and strip both delimiters and embedded whitespace.
Since the URI bracketing in an HREF attribute value is done using "..." or
'...', not "URL:..." or 'url:...', I cannot see any requirement on an HTML
browser to find and strip out the "url:".
Perhaps you might like to modify the validator to spot this form of error?
DMA.