Spread the light, my child.
Henzell says...
  1. o is auto-explore; which attempts to map your current floor with a basic AI that covers land as fast as possible. This is the second-best button in Crawl. See {tab} for the best one. Ctrl-O shows a basic dungeon (O)verview. o is an orc-type monster (see o[2]). O is an Ogre-type monster (see O[3]).
  2. see {orc [1]}
  3. see {ogre[1]}
  4. Saint Roka is the best o in Crawl.
  5. <}> o is a nasty hack that disguises the fact that 90% of crawl is boring

Information based on master branch and the great LearnDB.
© Dungeon Crawl Stone Soup, 2010.