enum:

  unidom_calculation:
    amount:
      code: AMNT
    percentage:
      code: PCTG

  unidom_charging:
    one_time:
      code: ONCE
      description: such as for buying a good
    recurring:
      code: RECR
      description: an ongoing charge such as a monthly fee for a standard type of service
    utilization:
      code: UTLZ
      description: usage of a product