Pages like https://lists.wikimedia.org/hyperkitty/list/wikitech-l@lists.wikimedia.org/ or https://lists.wikimedia.org/postorius/lists/ should have a custom footer which links to the Privacy Policy and probably to the CoC.
Compare e.g. Gerrit's https://gerrit.wikimedia.org/r/plugins/gitiles/operations/puppet/+/0ff3cb5dd9bf5f05cb77c6afb8898797f7380a29/modules/gerrit/files/homedir/review_site/etc/GerritSiteFooter.html
See also https://gitlab.com/mailman/postorius/-/issues/485 in upstream.
Mailing lists are not only used for technical things so the UCoC should probably be linked. Also, the non-wiki privacy policy https://foundation.wikimedia.org/wiki/Policy:Non-wiki_privacy_policy likely applies instead of the wiki one (this goes for Gerrit as well). Additionally, I don't see the CoC linked in Gitiles? I wonder if it could be added.
Additionally, I don't see the CoC linked in Gitiles? I wonder if it could be added.
This is out of scope for this task, Please avoid task creep by opening the relevant tasks.
I wonder if UCoC is a better option here. Most mailing lists are not covered by TCoC.