diff --git a/MdePkg/Include/Library/ScsiLib.h b/MdePkg/Include/Library/ScsiLib.h
index 2d4f0a43b6..4391adc812 100644
--- a/MdePkg/Include/Library/ScsiLib.h
+++ b/MdePkg/Include/Library/ScsiLib.h
@@ -98,11 +98,11 @@ ScsiTestUnitReadyCommand (
   @param[in]     ScsiIo             SCSI IO Protocol to use
   @param[in]     Timeout            The length of timeout period.
   @param[in]     SenseData          A pointer to output sense data.
-  @param[in out] SenseDataLength    The length of output sense data.
+  @param[in, out] SenseDataLength    The length of output sense data.
   @param[out]    HostAdapterStatus  The status of Host Adapter.
   @param[out]    TargetStatus       The status of the target.
-  @param[in out] InquirydataBuffer  A pointer to inquiry data buffer.
-  @param[in out] InquiryDataLength  The length of inquiry data buffer.
+  @param[in, out] InquiryDataBuffer  A pointer to inquiry data buffer.
+  @param[in, out] InquiryDataLength  The length of inquiry data buffer.
   @param[in]     EnableVitalProductData  Boolean to enable Vital Product Data.
 
   @retval EFI_SUCCESS                Command is executed successfully.
@@ -155,11 +155,11 @@ ScsiInquiryCommand (
   @param[in]     ScsiIo             A pointer to SCSI IO protocol.
   @param[in]     Timeout            The length of timeout period.
   @param[in]     SenseData          A pointer to output sense data.
-  @param[in out] SenseDataLength    The length of output sense data.
+  @param[in, out] SenseDataLength    The length of output sense data.
   @param[out]    HostAdapterStatus  The status of Host Adapter.
   @param[out]    TargetStatus       The status of the target.
   @param[in]     DataBuffer         A pointer to input data buffer.
-  @param[in out] DataLength         The length of input data buffer.
+  @param[in, out] DataLength         The length of input data buffer.
   @param[in]     DBDField           The DBD Field (Optional).
   @param[in]     PageControl        Page Control.
   @param[in]     PageCode           Page code.
@@ -215,7 +215,7 @@ ScsiModeSense10Command (
   @param[in]       ScsiIo               A pointer to SCSI IO protocol.
   @param[in]       Timeout              The length of timeout period.
   @param[in]       SenseData            A pointer to output sense data.
-  @param[in out]   SenseDataLength      The length of output sense data.
+  @param[in, out]   SenseDataLength      The length of output sense data.
   @param[out]      HostAdapterStatus    The status of Host Adapter.
   @param[out]      TargetStatus         The status of the target.
 
@@ -258,11 +258,11 @@ ScsiRequestSenseCommand (
   @param[in]     ScsiIo               A pointer to SCSI IO protocol.
   @param[in]     Timeout              The length of timeout period.
   @param[in]     SenseData            A pointer to output sense data.
-  @param[in out] SenseDataLength      The length of output sense data.
+  @param[in, out] SenseDataLength      The length of output sense data.
   @param[out]    HostAdapterStatus    The status of Host Adapter.
   @param[out]    TargetStatus         The status of the target.
   @param[out]    DataBuffer           A pointer to a data buffer.
-  @param[in out] DataLength           The length of data buffer.
+  @param[in, out] DataLength           The length of data buffer.
   @param[in]     PMI                  Partial medium indicator.
 
   @retval  EFI_SUCCESS                Command is executed successfully.
@@ -309,11 +309,11 @@ ScsiReadCapacityCommand (
   @param[in]     ScsiIo               A pointer to SCSI IO protocol.
   @param[in]     Timeout              The length of timeout period.
   @param[in]     SenseData            A pointer to output sense data.
-  @param[in out] SenseDataLength      The length of output sense data.
+  @param[in, out] SenseDataLength      The length of output sense data.
   @param[out]    HostAdapterStatus    The status of Host Adapter.
   @param[out]    TargetStatus         The status of the target.
   @param[out]    DataBuffer           Read 10 command data.
-  @param[in out] DataLength           The length of data buffer.
+  @param[in, out] DataLength           The length of data buffer.
   @param[in]     StartLba             The start address of LBA.
   @param[in]     SectorSize           The sector size.
 
@@ -362,11 +362,11 @@ ScsiRead10Command (
   @param[in]     ScsiIo               SCSI IO Protocol to use
   @param[in]     Timeout              The length of timeout period.
   @param[in]     SenseData            A pointer to output sense data.
-  @param[in out] SenseDataLength      The length of output sense data.
+  @param[in, out] SenseDataLength      The length of output sense data.
   @param[out]    HostAdapterStatus    The status of Host Adapter.
   @param[out]    TargetStatus         The status of the target.
   @param[out]    DataBuffer           A pointer to a data buffer.
-  @param[in out] DataLength           The length of data buffer.
+  @param[in, out] DataLength           The length of data buffer.
   @param[in]     StartLba             The start address of LBA.
   @param[in]     SectorSize           The sector size.