Rebate Agreement number in GL account line item in Assignment Field

Hi all

We have two GL accounts in company code xxx - 299011 and 373500. They both have the same sort key 016 but do not get the same value in the assignment field. For the 299011 account the system seems to add the Rebate agreement number to the field from the sort key. This is also requested for the 373500 account.

The document flow is like this Std order > outbound delivery > Invoice > Accounting Doc.

In GL a/c 299011 the agreement number is displayed but no rebate agreement number is displayed in account 373500. What are the setting need to be done to achieve rebate no in gl account 373500.

Thanks

Naveen