Notify is one of those. It keeps the current state of friendship you have (in/offered, out/pending or notify) and whether you are notifying this person of your presence. You can control this using the /friend, /unfriend and /notify commands.
The /show notify command tells you who you are informing of your presence. /show in shows offered friendships. /show out shows pending friendships.
The /cancel command lets you delete the entire record for a peer.
IRC also has a /notify command, but it's an old hack. Don't use it here.