Maximum number of characters is 9 and minimum is 2. This number is established by the ORI for agency use. Because an agency cannot use the same case number more than once if the base record information is the same, an alphabetic suffix should be used for multiple entries relating to the same case. Example: case 1234 assigned to three different persons 1234A, 1234B and 1234C. If the case number has a leading or trailing space, the space must be included exactly as entered. The characters “WI” in position one and two of the case number are not permitted. A single zero or run of zeros is not permitted.