Added a note to show about reorganizeand autocommit

Author: rrg92

docs/t-sql/statements/alter-index-transact-sql.md

@@ -251,11 +251,13 @@ PARTITION
  REORGANIZE a **rowstore** index  
  For rowstore indexes, REORGANIZE specifies to reorganize the index leaf level. The REORGANIZE operation is:  
 
--	It locks the object using schema shared locks (Sch-S) and exclusive locks. If another session reads data using NOLOCK hint, it will bypass the REORGANIZE (REBUILD blocks all, including statements with NOLOCK hint). Statements that modify data are always blocked.
 -   Not allowed for a disabled index  
 -   Not allowed when ALLOW_PAGE_LOCKS is set to OFF  
 -   Not rolled back when it is performed within a transaction and the transaction is rolled back.  
 
+> [!NOTE]
+> If using explicit transactions instead of the default implicit transaction mode (e.g., ALTER INDEX within BEGIN TRAN ... COMMIT/ROLLBACK), the locking behavior of REORGANIZE becomes more restrictive. For more information on implicit transactions, see [SET IMPLICIT_TRANSACTIONS (Transact-SQL)](../../t-sql/statements/set-implicit-transactions-transact-sql)
+
 For more information, see [Reorganize and Rebuild Indexes](../../relational-databases/indexes/reorganize-and-rebuild-indexes.md). 
 
 REORGANIZE WITH **(** LOB_COMPACTION = { **ON** | OFF } **)**