diff --git a/MdePkg/MdePkg.dec b/MdePkg/MdePkg.dec
index ac54338089..bec63f5416 100644
--- a/MdePkg/MdePkg.dec
+++ b/MdePkg/MdePkg.dec
@@ -2213,6 +2213,7 @@
   #  BIT20 - Global Coherency Database changes message.<BR>
   #  BIT21 - Memory range cachability changes message.<BR>
   #  BIT22 - Detailed debug message.<BR>
+  #  BIT23 - Manageability debug message.<BR>
   #  BIT31 - Error message.<BR>
   # @Prompt Fixed Debug Message Print Level.
   gEfiMdePkgTokenSpaceGuid.PcdFixedDebugPrintErrorLevel|0xFFFFFFFF|UINT32|0x30001016