rec.games.roguelike.misc is a usenet group for posting about various roguelikes that do not have their own groups. Crawl and POWDER are both popular on this group. Maintainers of these games seem to frequent this newsgroup.
When a roguelike game achieves great enough popularity it has its own newsgroup created. Last to reach this was ADOM. Hierarchy is unlikely to change again because it is better to let drown posts about less played game in crawl posts than to let it drown in spam.
It is wise to tag a post with name of roguelike game it is referring to. Please use dash characters to surround name games because google groups which recently is widely used to browse rgrm has a bug causing parts of subject in square brackets to be invisible.