Regarding the SHOULD for NFC in RDF Literals

Hello all,

I was asking myself another question regarding the "should" in 3.3. 
http://www.w3.org/TR/rdf11-concepts/#section-Graph-Literal

>   * a lexical form, being a Unicode [UNICODE
>     <http://www.w3.org/TR/rdf11-concepts/#bib-UNICODE>] string, which
>     /SHOULD/ be in Normal Form C [NFC
>     <http://www.w3.org/TR/rdf11-concepts/#bib-NFC>],
>

http://www.ietf.org/rfc/rfc2119.txt says regarding SHOULD:
> 3. SHOULD   This word, or the adjective "RECOMMENDED", mean that there
>     may exist valid reasons in particular circumstances to ignore a
>     particular item, but the full implications must be understood and
>     carefully weighed before choosing a different course.

I am not sure, what reasons could exist not to require NFC . N-Triples 
doesn't seem to use ASCII any more in its next version. What is the hold 
up to change this to a MUST and write a validation test case?

I am just asking out of curiosity. The topic is complex and the "full 
implications must be understood and carefully weighed before choosing a 
different course" justify a SHOULD as well.

All the best,
Sebastian


-- 
Dipl. Inf. Sebastian Hellmann
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