Identifies a number equivalent to the End User Purchase Order Number.
NOTE 1: This may, at the option of the customer, be a requirement when providing service to some governmental agencies.
NOTE 2: This field may be used in conjunction with the SBILLNM field.
USAGE: This field is optional.
DATA CHARACTERISTICS: 30 alpha/numeric characters
EXAMPLE: A B 1 2 3 4 5 6 7 8