In <41541BE8(_dot_)7030702(_at_)erols(_dot_)com> Bruce Lilly
<blilly(_at_)erols(_dot_)com> writes:
Temporarily leaving aside "strip these angle brackets", there
are several issues that should be taken into consideration
when comparing identifiers:
* domain names are case-insensitive, so
"<1234(_at_)foo(_dot_)example(_dot_)net>"
is semantically identical to "<1234(_at_)FoO(_dot_)ExAmPlE(_dot_)nEt>". RFC
2822 presents a problem here, because a receiver can never
be sure whether or not an RFC 2822 id-right is a case-
insensitive domain name or something else (which might be
case-sensitive).
No, I don't think that is right. An id-right, as defined by RFC 2822, is a
string of characters, possibly subject to special semantics for any
quoted-string or quoted-pair. The suggestion to use a domain name as that
string does not mean that it IS a domain name once copied into an
id-right. It IS now an id-right and is subject to whatever semantic rules
apply to an id-right, and no others.
* local-parts and domain literals need to be canonicalized
w.r.t. quoting conventions prior to comparisons. The
following are all semantically identical:
<foo(_dot_)bar(_at_)[1(_dot_)2(_dot_)3(_dot_)4]> (canonical form)
<"foo.bar"@[1\.2.3.4]>
<"f\oo.bar"@[1\.2.3.4]>
<"f\oo\.bar"@[1\.2.3.4]>
<"f\oo\.bar"@[1\.\2.3.4]>
Yes, that is indeed true within Email, but it is not true (and cannot be
true) within Netnews. Which is why I would like to see that tidied up next
time RFC 2822 comes up for review.
--
Charles H. Lindsey ---------At Home, doing my own thing------------------------
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