why this page
I’ve found myself presenting my schema for scan/spam containment on Telegram to different people, writing more or less each time the same stuff. this page summarizes the policy I developed.
why a Telegram group?
it was the path of least resistance, I started simultaneously exploring the official Wiki pages, and the official forum for Panamá, and we missed a mailing list. after a fruitless attempt at creating one, I made a “temporary” Telegram group, which is still there while I don’t think a mailing list would be of any extra value, in particular considering the activity on the talk-latam mailing list, kept alive by the weekly link to the newsletter.
where do I use this?
the Comunidad OSM Panamá and the OpenStreetMapOffTopic are the two groups I manage thanks to a @MissRose_bot administrator, with similar settings.
what is the user experience?
a new user is offered a text telling them what is the group, where they need to click on a button within a short period of time, and inviting them to provide a short message for the people already in the group. in my experience, scammers tend to join several groups at the same time, and will not care to read this invitation, so they can be kicked from the group before they come back to it.
welcome text will disappear after they have been acknowledged by the new user, or when the new user is kicked from the group. the idea is not to clutter the group with technical messages. the bot will also delete all joining and leaving notifications, which I also consider cluttering.
join and leave notifications will be logged to a parallel channel, meant for administrators or for anybody wondering about how much work it is, to administer a Telegram group.
any administrative action like banning users will be taken in a parallel group, only meant to receive commands to the bot, again reducing clutter in the group.

