Field help (TPYCIB) 

The Inter-banking code is a coding used by all banks to indicate the bank operation type on the lines of the bank statements that are sent to their customers.
In X3, this code refers to miscellaneous table 306.
The accounting journals also have an inter-bank code. It is use to facilitate (sort, selection) and to control the bank reconciliation (RAPBAN function) between the postings in a bank account with the lines in the bank statements.
The code entered here can be transmitted to the posting documents for the payments via the automatic payment journals.