ietf-nntp new draft of the NNTP spec released

[Russ Allbery]

[ Resending a previous message because I wasn't subscribed properly. ]

Charles Lindsey <chl at clw.cs.man.ac.uk> writes:

> But in the end I suspect that compatibility with existing INN practice
> is what we really want, so it would be useful to document what that
> is.

I'm not completely happy with this explanation yet, since the description
of poison wildcards isn't yet quite what is done in practice.  But it's
relatively decent for exclusion wildcards.  This is from INSTALL in INN
2.3.

    Before we begin, it is worth mentioning the wildmat pattern matching
    syntax used in many configuration files.  These are simple wildcard
    matches using the asterisk (`*') as the wildcard character, much like
    the simple wildcard expansion used by Unix shells.

    In many cases, wildmat patterns can be specified in a comma-separated
    list to indicate a list of newsgroups.  When used in this fashion, each
    pattern is checked in turn to see if it matches, and the last pattern in
    the line that matches the group name is used.  Patterns beginning with
    `!' mean to exclude groups matching that pattern.  For example:

        *, !comp.*, comp.os.*

    In this case, we're saying we match everything (`*'), except that we
    don't match anything under comp (`!comp.*'), unless it is actually under
    the comp.os hierarchy (`comp.os.*').  This is because non-comp groups
    will match only the first pattern (so we want them), comp.os groups will
    match all three patterns (so we want them too, because the third pattern
    counts in this case), and all other comp groups will match the first and
    second patterns and will be excluded by the second pattern.

    Some uses of wildmat patterns also support "poison" patterns (patterns
    starting with `@').  These patterns behave just like `!' patterns when
    checked against a single newsgroup name.  Where they become special is
    for articles crossposted to multiple newsgroups; normally, such an
    article will be considered to match a pattern if any of the newsgroups
    it is posted to matches the pattern.  If any newsgroup the article is
    posted to matches an expression beginning with `@', however, that
    article will not match the pattern even if other newsgroups to which it
    was posted match other expressions.

    See wildmat(5) for full details on wildmat patterns.

-- 
Russ Allbery (rra at stanford.edu)         <URL:http://www.eyrie.org/~eagle/>