X matches any digit from 0-9
Z matches any digit from 1-9
N matches any digit from 2-9
[1237-9] matches any digit or letter in the brackets (in this example, 1,2,3,7,8,9)
. wildcard, matches one or more characters
! wildcard matches zero or more characters
Wildcard characters, if used, must be the final character in the dial pattern
Here is the standard 10 digit NANP (North American Numbering Plan) dial pattern:
NXXNXXXXXX
From above, we can see that this pattern could also be written as:
[2-9]XX[2-9]XXXXXX
It is common for NANP numbers to have the leading digit 1 (country code), but note you can't represent both number formats with a single pattern. You must use two separate patterns:
NXXNXXXXXX 1NXXNXXXXXX
Not stated above, digits are permitted in dial patterns of course. If you want to create a dial pattern(s) to match all numbers for area code 920:
920NXXXXXX 1920NXXXXXX