What Is a Reference Number?
A reference number is a unique identifier assigned to any financial transaction happening. The reference number is created technologically and designated for a single transaction. A reference number helps an institution identify transactions in records and electronic databases used to monitor transactions associated with a card. 

The reference number generated can be customized according to the business requirements. This feature is possible in DOKA SAAS using transaction DBxREF.

Transaction - DBxREF 

This transaction DBxREF is used to customize the configuration of reference numbers as per the bank's requirement. Please note, the configuration is common for the entire entity group.
The primary requirements in reference number logic in a contract are to identify the below details
a) Business module / Product code: Either the business module the contract belongs to, such as Import LC or Guarantee, etc., or the product code the contract belongs to, could be selected to be a part of the reference number. Product code can be derived from maintaining product codes (DBxPRD) if available or can also be manually given in DBxREF.
b) Entity code / Entity name: Either branch code or branch name could be selected to be a part of the reference number.
c) Year: The year the contract was created
Therefore, the structure of reference numbers contains the above iterations. Additionally, other normal requirements such as counter (running sequence), special characters, and sequences are also a part of the reference number's structure.