> In any case, the appropriate section from the URL draft (version 8) is:
>
> Characters can be unsafe for a number of reasons. The space
> character is unsafe because significant spaces may disappear and
> insignificant spaces may be introduced when URLs are transcribed or
> typeset or subjected to the treatment of word-processing programs.
> The characters "<" and ">" are unsafe because they are used as the
> delimiters around URLs in free text; the quote mark (""") is used
> to delimit URLs in some systems. The character "#" is unsafe and
> should always be encoded because it is used in World Wide Web and
> in other systems to delimit a URL from a fragment/anchor identifier
> that might follow it. The character "%" is unsafe because it is
> used for encodings of other characters. Other characters are
> unsafe because gateways and other transport agents are known to
> sometimes modify such characters. These characters are "{", "}",
> "|", "\", "^", "~", "[", "]", and "`".
Looks like they forgot one: Ampersand (&), which is used
as the entity reference open delimiter in HTML.
--Joe English
jenglish@crl.com