Planner has two modules available for keeping track of contact and conversation information. The first uses the Big Brother Database (BBDB), and the second uses Emacs Relay Chat (ERC). BBDB is a full contact database. ERC is a client for chatting online on Internet Relay Chat (IRC) networks. The ERC module for Planner will help you keep track of online conversations you have if you use ERC for those conversations, but does not by itself store contact information other than the time you had the conversation, the network and channel you were on when you had it, and maybe who you had it with. If you are looking for a way to manage your full address book, then planner-bbdb.el in combination with BBDB is what you are looking for.