Introducing list "topics"

[text at sdfeu.org]

On Sat, 19 Dec 2020 23:51:39 +0100, Solderpunk wrote:
> On Sat Dec 19, 2020 at 11:39 PM CET, Sean Conner wrote:
>> Oh, and can an email be in two or more topics? Like "[ann] [tech]"?
> 
> They're case insensitive. The GNU Mailman docs don't actually seem to
> answer your second question. I would tentatively guess that an email
> *can* be in two topics.

Mailman code confirms, if I'm not mistaken:

https://bazaar.launchpad.net/~mailman-coders/mailman/2.1/view/head:/
Mailman/Handlers/Tagger.py

    for name, pattern, desc, emptyflag in mlist.topics:
        pattern = OR.join(pattern.splitlines())
        cre = re.compile(pattern, re.IGNORECASE)
        for line in matchlines:
            if cre.search(line):
                hits[name] = 1
                break

This list currently run by mailman 2.1.34; V3 is still working on topics:
https://gitlab.com/mailman/mailman/-/blob/master/src/mailman/handlers/
member_recipients.py#L92