This function is used to standardize UK postal codes, which contain alphanumeric characters.

Output Type
MinFldArgs, MaxFldArgs
Minlength, Max Length
  1. The non-alphanumeric characters are first removed from the string.
  2. The length of the attribute is checked.
    1. If the length is 0, the attribute is treated as ANON.
    2. If the length is less than the minimum (Min) value (5), the attribute is treated as ANON.
    3. If the length is greater than maximum (Max) value (7), the attribute is truncated to the max value.
  3. If there is an ANON table and if the attributes are listed in this table, it is treated as ANON.
  4. If the EQUI table is specified and if the attribute does not belong there, it is treated as ANON.
  5. Finally, the output is added to the comparison string.