The distinction between these two major categories is that collections credited to appropriation or fund accounts are offset within the account that contains the associated disbursements (outlays), whereas offsetting receipts are in accounts separate from the associated disbursements.
The two categories have been set up this way by federal regulations.
mnli hypothesis: The two categories have been set up this way by federal regulations. premise: The distinction between these two major categories is that collections credited to appropriation or fund accounts are offset within the account that contains the associated disbursements (outlays), whereas offsetting receipts are in accounts separate from the associated disbursements.