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Issue for RFC 2396bis: %HH scheme dependent ???

From: Martin Duerst <duerst@w3.org>
Date: Thu, 30 Jan 2003 15:55:29 -0500
Message-Id: <>
To: uri@w3.org
Cc: "Tim Berners-Lee" <timbl@w3.org>

Hello Roy, others,

Doing careful readings of RFC 2396 for various purposes, I found
the following paragraph in "2.1 URI and non-ASCII characters":

    A URI scheme may define a mapping from URI characters to octets;
    whether this is done depends on the scheme. Commonly, within a
    delimited component of a URI, a sequence of characters may be used to
    represent a sequence of octets. For example, the character "a"
    represents the octet 97 (decimal), while the character sequence "%",
    "0", "a" represents the octet 10 (decimal).

This seems to indicate that a scheme is free to define whether it
wants to use %0a for the octet 10 (decimal) or not, and whether
it indeed wants to define a mapping from URI characters to octets.

As far as I understand, %hh is always usable, and I don't know
about any schemes that define explicitly that this can be used.
It may have been that this paragraph was written to take into
account schemes such as data:, where an additional mechanism
for encoding octets (base64) is used. My understanding is that
even in a data: URI, I should still be able to replace "A" by
"%41", and it should still resolve to the same data.

Can this please be corrected/clarified?

I have not found this issue at

Regards,    Martin.
Received on Thursday, 30 January 2003 16:05:04 UTC

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