Follows a listing by DM without joining it. Pick the listing from the autocomplete or type part of its title; the match is made among this server's open and full listings. If Group Finder is switched off for the server the reply is Not enabled.
The command is a toggle. The first run replies Now watching **{title}** and promises DMs when it changes; running it again on the same listing replies Stopped watching **{title}**. Nothing found gives No active listing found.
Watchers are DMed when someone joins, joins the waitlist or leaves, when an applicant is approved, when the listing closes (by the leader, by an admin or because the leader left), about 15 minutes before a scheduled start, when a time poll sets the start time, and when the next run of a repeating group is posted.
The Watch button on the listing card does the same thing. /group watching lists everything you follow.