# Attendee guidelines

First make sure that you sign up to [the brainhack mattermost](https://mattermost.brainhack.org/brainhack/channels/hbm-hackathon) (the open-source messsenging system equivalent to Slack) and that you join the [hbm-hackathon channel](https://mattermost.brainhack.org/brainhack/channels/hbm-hackathon) where we will be sharing information regularly.

If you are not familiar with mattermost, make sure you check out the [user-guide](https://docs.mattermost.com/guides/user.html) and that [short video](https://www.youtube.com/watch?v=eq4yEM5z5SY&list=PL-jqvaPsjQpMqnRgFEw_3fuGQbcVDTpaM&index=5) describing how it works.