Checks on Critical Business Transactions 
Use
If the Enhanced Function of the Payment Selection is active, some technical posting restrictions are required in order to guarantee the correct conversion of payments in Funds Management (FM).
An up-to-date overview and documentation of the critical business transactions can be found in SAP note 400924.
Features
To prevent errors occurring with the payment selection and payment matching later on, you can define the following system messages to suit your requirements in Customizing for Funds Management in the message control (message class FICUSTOM).
Payment reference
100 document line item &1 &2 &3 &4 does not contain any clearing information
Residual item/partial payment
101 invoice reference &1 &2 &3 does not refer to an invoice
Fiscal year; date of payment conversion
103 carry forward commitment after posting the invoice &1 &2 &3
Branched posting
105 branched posting; the document contains &1 subledger accounts
Special G/L
106 you use the Special G/L indicator &1 in invoice &2 &3 &4
The following critical business transactions are caught by error messages:
Cross-Company Code Transactions
107 posting is not possible; FM is not active in company code &1
Clearing reset
108 posting not possible; clearing reset of transfer requires reversal
Activities
To adjust these system messages to suit your requirements, you must define them accordingly in the Implementation Guide of
Funds Management Government
, under
Basic Settings 
ChangeMessage Control 
.