Bill Message Information
One record for every bill message linked to the bill.
| Field Name | Format | Source/Value/Description | 
| MSG_PRIORITY_FLG | A12 | CI_BILL_SA or CI_FT | 
| INSERT_CD | S15.2 | CI_BILL_SA or CI_FT | 
| MSG_ON_BILL | S15.2 | CI_BILL_SA or CI_FT | 
