i believe the * option is for multiple commands with the same beginning. like, set up a handler for /user* and the bot will see /username, /usernickname, /usericon, or any other command starting with /user. if you leave off the asterisk, only typing /user will trigger the bot. whether you use a * or not your bot always gets everything after the space; those are the parameters to the function.
/user - works
/user* - works
/user * - same as /user, so pointless (like you've found out)