[Mailman-Developers] [Mailman-Announce] Mailman 2.1.10b4 Released

[Ian Eiloart]

--On 13 March 2008 19:26:54 -0700 Mark Sapiro <mark at msapiro.net> wrote:

>
> - - Added a new 'sibling list' feature to exclude members of another list
> from receiving a post from this list if the other list is in the To: or
> Cc: of the post or to include members of the other list if that list is
> not in the To: or Cc: of the post (Patch ID 1347962).

I don't understand this feature.... Hmm, Tokio Kikuchi asked about the name 
in 2005. I'm sorry that I didn't comment earlier.

<https://sourceforge.net/tracker/?func=detail&atid=300103&aid=1347962&group_id=103>

Sibling is a *completely* misleading term for this feature, because sibling 
relationships are necessarily symmetrical: if A is a sibling of B, then B 
must be a sibling of A. This feature is necessarily anti-symmetrical, more 
like "child" or "descendent". The term "sibling" will lead people to 
misconfigure their lists.

<http://en.wikipedia.org/wiki/Symmetric_relation>
<http://en.wikipedia.org/wiki/Antisymmetric_relation>

Question: is the relationship also transitive? IE, if C is a child of B, 
and B is a child of A, then will postings to A go to members of C? If so, 
then the relationship should be called "descendent".

<http://en.wikipedia.org/wiki/Transitive_relation>

As far as inclusion is concerned, we then have a partially ordered set of 
mailing lists under this relationship. If the code handles the (presumably 
erroneous case) where a list is marked as a "sibling" of itself properly 
(ie, the listing should be ignored).

<http://en.wikipedia.org/wiki/Partial_order>


-- 
Ian Eiloart
IT Services, University of Sussex
x3148