Beginning with Release 3.0, you can assign the activity "RFRK" to a ledger. In the SAP system, this activity stands for reconciliation postings which are generated by reconciliation ledgers in financial accounting. Using these postings, the cross-company code or cross-business area value flows from controlling are defined. A ledger which has CO activities assigned to it, contains internal CO allocations. If the activity "RFRK" is also assigned to such a ledger, the cross-company code or the cross-business area value flows will be written twice. This is unnecessary.
A ledger should not contain both the CO activities and the activity "RFRK".