Quote:
although I don't think the command depends on the server...


It is. mIRC has to adjust the command output depending on the server software, because many servers are not smart enough to handle @#channel messages.

Code:
       |           |          |          | undernet  |          
       |           |          |          | quakenet  |          
       |  dalnet   |  efnet   |  ircnet  | gamesurge |          
       | (bahamut) | (hybrid) |          |   (ircu)  | (unreal) 
       |           |          |          |           |          
       |           |          |          |           |          
notice |    @+#    |    @#    |    -     |     @#    |   @+#    
       |           |          |          |           |          
 msg   |    @+#    |    -     |    -     |     -     |   @+#    
       |           |          |          |           |