Choose Number Management - Restricted Numbers in the main menu, to view the table of restricted numbers.
Use New in the toolbar to create new numbers, which cannot be dialled from the system. Partial numbers, such as 49900 are allowed.
In the column Action you can Edit or Delete restricted numbers, assuming you have rights to use those functions.
A restricted number can be used as part of regular expression, that will be used in the following context '^<regex>.*' .
Ex: By using a restricted number '.*666', all numbers, which contain 666, will be rejected.
Note, that some numbers may be restricted by settings made by the system administrator. These numbers cannot be changed.