; X - any digit from 0-9
; N - any digit from 2-9
; [1235-9] - any digit in the brackets (in this example, 1,2,3,5,6,7,8,9)
-; . - wildcard, matches anything remaining (e.g. _9011. matches anything starting with 9011 including 9011)
+; . - wildcard, matches anything remaining (e.g. _9011. matches anything starting with 9011 excluding 9011 itself)
;
; For example the extenion _NXXXXXX would match normal 7 digit dialings, while
; _1NXXNXXXXXX would represent an area code plus phone number