Ive been struggling with certain elements of wildcards and digit matching.
This is an excellent overview of all special characters used in matching digits with CUCM:
http://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/7_1_2/ccmsys/accm-712-cm/a03rp.html#wp1043520
It also contains examples next to each special characters making the concept easier to understand.