diff --git a/MdePkg/Include/Uefi/UefiSpec.h b/MdePkg/Include/Uefi/UefiSpec.h
index e8feed120d..57cb4e804f 100644
--- a/MdePkg/Include/Uefi/UefiSpec.h
+++ b/MdePkg/Include/Uefi/UefiSpec.h
@@ -1004,11 +1004,15 @@ EFI_STATUS
 
   @param[in]  ResetType         The type of reset to perform.
   @param[in]  ResetStatus       The status code for the reset.
-  @param[in]  DataSize          The size, in bytes, of WatchdogData.
+  @param[in]  DataSize          The size, in bytes, of ResetData.
   @param[in]  ResetData         For a ResetType of EfiResetCold, EfiResetWarm, or
                                 EfiResetShutdown the data buffer starts with a Null-terminated
                                 string, optionally followed by additional binary data.
-
+                                The string is a description that the caller may use to further
+                                indicate the reason for the system reset. ResetData is only
+                                valid if ResetStatus is something other than EFI_SUCCESS
+                                unless the ResetType is EfiResetPlatformSpecific
+                                where a minimum amount of ResetData is always required.
 **/
 typedef
 VOID