I've been meaning to open this task for a while but I guess I've been shy about it.
https://phabricator.wikimedia.org/settings/panel/contact/ is avalaible for some time. As far as I could see at https://secure.phabricator.com/D19988 this is a new feature to Phabricator can send SMS messages for authentication purposes. I guess this requires configuring some additional infraestructure for sending such messages.
Does this feature work for our Wikimedia Phabricator install? If not, can it be disabled so no one can use it? (apparently this is possible)
If the feature does work for Wikimedia, can we document it elsewhere on mediawiki or Wikitech?
Upstream ticket: https://we.phorge.it/T15486