Bukkit

Default_Join_Msg: false < If set to true, this will set the player join messages to default.
Default_Quit_Msg: false < If set to true, this will set the player quit messages to default.
PlayerJoinMsg: §6Welcome %player! < The message broadcasted when a normal player joins.
PlayerQuitMsg: §6Goodbye %player! < The message broadcasted when a normal player quits.
OpJoinMsg: §6Hey everyone! %player has joined the game! < The message broadcasted when an op joins.
OpQuitMsg: §6Farewell %player! < The message broadcasted when an op quits.
DisablePlayerNameCaps: false < If set to true, this will disable capital letters in the player name.
MinimumPlayersForJoinMsg: 0 < Minimum amount of players to be online for join message to work.
MaximumPlayersForJoinMsg: 9999 < Maximum amount of players to be online until join message stops.
MinimumPlayersForQuitMsg: 0 < Minimum amount of players to be online for quit message to work.
MaximumPlayersForQuitMsg: 9999 < Maximum amount of players to be online until quit message stops.

NOTES:

1. Use the § symbol for color codes. You may also use formatting codes. Example: §4Hello!
2. Use %player to reference the player in the join/quit messages.
3. Default join/quit messages at the top at the config essentially disables the plugin and overrides ALL settings below it.