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When is percent-encoding required.

From: Charles Lindsey <chl@clerew.man.ac.uk>
Date: Mon, 04 Jan 2010 18:12:55 -0000
To: URI <uri@w3.org>
Message-ID: <op.u50svt1r6hl8nm@clerew.man.ac.uk>
Draft-ellermann-news-nntp-uri-11.txt is currently going through AUTH48  
and, since Frank Ellermann seems not to have been heard from for more than  
a year, and cannot be contacted, I am getting the job of seeing what needs  
to be done (most notably changes necessitated by the AUTH48 changes in RFC  

I find the question of just what needs to be percent-emcoded is hard to  
deduce from RFC 3986. Clearly, anything in <gen-delims> MUST be  
percent-encoded except when used as delimiters, so that agents can divide  
a URI into scheme, authority, path, query, and fragment components even  
before they recognise that it is a news or nntp URI. But is it REQUIRED  
for the <sub-delims> if the particular scheme does not use any of them as  
delimiters? RFC 3986 seems to imply not, so I would expect that in
(yes, "bar.!#$%&'*+/=?^`{|}.example" is a valid <dot-atom-text> and hence  
can occur in a Message-ID) I would have to percent-encode the '#'. '/' and  
'?', but not the others. Frank seems to have taken the view that all  
<sub-delims> need to be encoded, though he does at one point permit '*' to  
appear unencoded (and it was indeed explicitly allowed in RFC 1738), which  
appears to be inconsistent wuth his stance elsewhere

And he also includes an example
where I would have thought he could have shown

So exactly what latitude does RFC 3986 permit in these situations?

Charles H. Lindsey ---------At Home, doing my own thing------------------------
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Received on Monday, 4 January 2010 18:13:30 UTC

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