From the Method properties, there is a check box titled Invisible.
This feature is really nice. Checking this box means that this method will not be displayed by 4D when using the database. This could help you to prevent users from launching random methods from User mode or Custom menus. If you go to User Mode and ask to execute a method, you will not be able to see any method marked as Invisible. If you ask a 4D formula dialog (APPLY FORMULA/EDIT FORMULA from query and sorting dialogs), you will not be able to see invisible methods. However, this does not prevent the user from typing the method name to be executed.