5. A method as set forth in claim 3 , further comprising: designating the telephone number as the patterned telephone number if the letter combination forms any of the alphanumeric patterns.
3. A method as set forth in claim 1 , wherein identifying those of the telephone numbers that have digits that occur in any of the alphanumeric patterns defined by the second reference list includes: assigning at least one letter in an alphabet to a first digit; assigning at least one other letter in an alphabet to a second digit; identifying a letter combination created by at least two of the digits of the telephone number; and determining whether the letter combination is included in the second reference list as an alphanumeric pattern.