The * means all values that are listed in the section acess table. Puting nothing or blank means all values.
This will work in the developer, but on the server it will not work unless you disable the option in Document Properties -> Opening -> Strict Exclusion. If this is selected you must explicitly define the choices of each user, which is the best way to secure your QlikView.
Using blank o * with work fine if you're an Admin, but you want to consider joining the 10 users with all the possible values in the QlikView script so that the values are explicitly defined and you don't have to do it manually. Something like the join below to get the cross product between the users that see all and all the data that they can see:
1 as ID_Users
1 as ID_Users,
Employee //All employees that exist