I have created some custom commands for my MTM. They show up when one message is selected, but if I select multiple the command is not visible in the options menu. For example, I created Mark as read:

MTUD_FUNCTION
{
functiontext=STR_MARK_UNREAD;
command=ECommandMarkAsUnread;
flags=EMtudContextSpecific|EMtudAsynchronous|EMtudCommandTransferReceive;
},


I'm not really sure about the use of the flags. Are they explained anywhere? I want it to be similar to "Delete" where you can select many and execute the command. Anyone know what I need to add to be able to do this?

Thanks!