...

In the Contract field, you can select a particular contract if you need separate account to register the transactions related to this contract.

The GL Accounts section

In the Accounts Receivable field, specify the account to record the customer company's debt to the entity (if selected in the Entity field).

...

The PDCs Issued field is intended for the account to be used for recording the post-dated cheques issued by the entity to this company.

The toolbar buttons

Click Save and Close to save the item default accounts or changes to such accounts. Click Close to close the form without saving.

...