Game creator's personal message
When creating a game or tournament, players can set a personal message to attach to that game or tournament.
This message is visible to all players in the settings dialog, and it's also sent out to players that elect to receive e-mail notifications.
When inviting new players, it's a good idea to give a personalized greeting so they know who is sending them this invitation, as your friends may not recognize your game handle.
This is also a good place to explain the settings used, or to explain any custom rules in use.