Clarify cleanup

Author: dimitri-furman

docs/relational-databases/system-stored-procedures/sys-sp-persistent-version-cleanup-transact-sql.md

@@ -23,7 +23,7 @@ monikerRange: ">=sql-server-ver15 || >=sql-server-linux-ver15 || =azuresqldb-mi-
 
 [!INCLUDE [SQL Server 2019, ASDB, ASDBMI-fabricsqldb](../../includes/applies-to-version/sqlserver2019-asdb-asdbmi-fabricsqldb.md)]
 
-Manually starts persistent version store (PVS) cleanup process, a key element of accelerated database recovery (ADR). This cleaner also removes uncommitted changes in PVS from aborted transactions, known as the asynchronous logical revert process.
+Manually starts persistent version store (PVS) cleanup process, a key element of accelerated database recovery (ADR). The cleaner removes obsolete row versions from the in-row and off-row [PVS storage](../sql-server-transaction-locking-and-row-versioning-guide.md#space-used-by-the-persistent-version-store-pvs), and also removes uncommitted changes in PVS from aborted transactions.
 
 It isn't typically necessary to start the PVS cleanup process manually using `sys.sp_persistent_version_cleanup`. However in some scenarios, you might want to initiate the PVS cleanup process manually during a known period of rest/recovery after busy OLTP activity.
 
@@ -58,8 +58,8 @@ Optional. The option to determine the type of cleanup to perform. *@clean_option
 | Value | Description |
 | --- | --- |
 | `0` | Default, perform all cleanup. |
-| `1` | Clean up the off-row [version storage](../sql-server-transaction-locking-and-row-versioning-guide.md#space-used-by-the-persistent-version-store-pvs) without examining PVS page contents. Faster, but might skip deallocation of unused pages in PVS. |
-| `2` | Clean up the off-row [version storage](../sql-server-transaction-locking-and-row-versioning-guide.md#space-used-by-the-persistent-version-store-pvs) by checking each PVS page contents. Slower, but deallocates all unused pages. |
+| `1` | Clean up the off-row [version storage](../sql-server-transaction-locking-and-row-versioning-guide.md#space-used-by-the-persistent-version-store-pvs) without examining PVS page contents. Faster, but might skip deallocation of unused pages in PVS. This is the default behavior when `@clean_option` is omitted or set to `0`. |
+| `2` | Clean up the off-row [version storage](../sql-server-transaction-locking-and-row-versioning-guide.md#space-used-by-the-persistent-version-store-pvs) by checking each PVS page contents. Slower, but always deallocates all unused pages. |
 | `3` | Clean up the in-row [version storage](../sql-server-transaction-locking-and-row-versioning-guide.md#space-used-by-the-persistent-version-store-pvs) only. |
 | `4` | Clean up row versions generated by aborted transactions only (also known as logical revert). |