With Messenger Plus! you can use commands such as
/block in a conversation window to do a specified action. By typing this command in a conversation window and pressing Enter or clicking Send, the text will not be send but the command will be executed. For
/block this means your contact will be blocked.
For a full list of the commands Messenger Plus! offers see
http://www.msgplus.net/help_cmdtag.php.
Plugins can add new functionality to your Messenger, which means some of them also add new commands like those. The ColorNick plugin adds
/xcolornick. When you use
/xcolornick in a conversation window a new window will pop up where you can easily edit your nickname and easily put colour in it.