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Re: URI Comparisons: RFC 2616 vs. RDF

From: Nathan <nathan@webr3.org>
Date: Mon, 17 Jan 2011 16:57:10 +0000
Message-ID: <4D3474E6.4010403@webr3.org>
To: Kingsley Idehen <kidehen@openlinksw.com>
CC: Martin Hepp <martin.hepp@ebusiness-unibw.org>, public-lod@w3.org, Sandro Hawke <sandro@w3.org>
Kingsley Idehen wrote:
> On 1/17/11 10:51 AM, Martin Hepp wrote:
>> Dear all:
>>
>> RFC 2616 [1, section 3.2.3] says that
>>
>> "When comparing two URIs to decide if they match or not, a client  
>> SHOULD use a case-sensitive octet-by-octet comparison of the entire
>>    URIs, with these exceptions:
>>
>>       - A port that is empty or not given is equivalent to the default
>>         port for that URI-reference;
>>       - Comparisons of host names MUST be case-insensitive;
>>       - Comparisons of scheme names MUST be case-insensitive;
>>       - An empty abs_path is equivalent to an abs_path of "/".
>>
>>    Characters other than those in the "reserved" and "unsafe" sets (see
>>    RFC 2396 [42]) are equivalent to their ""%" HEX HEX" encoding.
>>
>>    For example, the following three URIs are equivalent:
>>
>>       http://abc.com:80/~smith/home.html
>>       http://ABC.com/%7Esmith/home.html
>>       http://ABC.com:/%7esmith/home.html
>> "
>>
>> Does this also hold for identifying RDF resources
> 
> Yes, where an RDF resource is a Data Container at an Address (URL). 
> Thus, equivalent results for de-referencing a URL en route to accessing 
> data.
> 
> No, when "resource" also implies an Entity (Data Item or Data Object) 
> that is assigned a Name via URI.

Logically, yes on both counts, we should/could be normalizing these URIs 
as we consume and publish using the syntax based normalization rules [1] 
which apply to all URI/IRIs with the generic syntax (such as the 
examples above)

Any client consuming data, or server publishing data, can use the 
normalization rules, so it stands to reason that it's pretty important 
that we all do it to avoid false negatives.

[1] http://tools.ietf.org/html/rfc3986#section-6.2.2

Best,

Nathan
Received on Monday, 17 January 2011 16:57:58 UTC

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