When a PO Receipt is created in the Receiving Transactions form with destination type as Inventory, 2 entries get created in the RCV_TRANSACTIONS form. One with Transaction type as Deliver and other with Receive. Also accounting is also derived for the 'RECEIVE' transaction. You will see an entry with RECEIVING_INSPECTION and an ACCRUAL entry in the RCV_RECEIVING_SUB_LEDGER table. When "Create Accounting: Receiving" is run, these Accrual Transaction for Receipt is transferred to GL through SLA. In SLA for Receive Transactions "Receiving Inspection" account is Debited and "Accrual" Account is credited. Journal Category will be "Receiving" for these transactions
For the Deliver Transaction type the transaction is sourced to Material Transactions as "PO Receipt" Transaction Type. Accounting will be done on this transaction when "Active Cost Worker" program is run. Usually this program will be scheduled to run every few minutes to calculate cost of the transactions. When "Accounting Program" is run, these transactions from MTL_TRANSACTION_ACCOUNTS will be transferred to GL through SLA. In SLA for Deliver Transactions, "Inventory Valuation" account is Debited and "Receiving Inspection" account is Credited. Journal Category will be "Inventory" for these Deliver Transactions.