diff --git a/MdePkg/Include/Guid/DxeServices.h b/MdePkg/Include/Guid/DxeServices.h
index e7b6b19eb0..358c08d72a 100644
--- a/MdePkg/Include/Guid/DxeServices.h
+++ b/MdePkg/Include/Guid/DxeServices.h
@@ -12,6 +12,10 @@
 #ifndef __DXE_SERVICES_GUID_H__
 #define __DXE_SERVICES_GUID_H__
 
+//
+// The DXE Services Table shall be stored in memory of type
+// EfiBootServicesData
+//
 #define DXE_SERVICES_TABLE_GUID \
   { \
     0x5ad34ba, 0x6f02, 0x4214, {0x95, 0x2e, 0x4d, 0xa0, 0x39, 0x8e, 0x2b, 0xb9 } \
diff --git a/MdePkg/Include/Guid/HobList.h b/MdePkg/Include/Guid/HobList.h
index 435f010c1a..6195fa9260 100644
--- a/MdePkg/Include/Guid/HobList.h
+++ b/MdePkg/Include/Guid/HobList.h
@@ -14,6 +14,10 @@
 #ifndef __HOB_LIST_GUID_H__
 #define __HOB_LIST_GUID_H__
 
+//
+// The HOB List Table shall be stored in memory of type
+// EfiBootServicesData
+//
 #define HOB_LIST_GUID \
   { \
     0x7739f24c, 0x93d7, 0x11d4, {0x9a, 0x3a, 0x0, 0x90, 0x27, 0x3f, 0xc1, 0x4d } \
diff --git a/MdePkg/Include/Guid/VectorHandoffTable.h b/MdePkg/Include/Guid/VectorHandoffTable.h
index ef9841e324..68353e826c 100644
--- a/MdePkg/Include/Guid/VectorHandoffTable.h
+++ b/MdePkg/Include/Guid/VectorHandoffTable.h
@@ -19,6 +19,9 @@
 // in case an entity in DXE wishes to update/change the vector
 // table contents.
 //
+// The table shall be stored in memory of type
+// EfiBootServicesData
+//
 #define EFI_VECTOR_HANDOF_TABLE_GUID \
   { 0x996ec11c, 0x5397, 0x4e73, { 0xb5, 0x8f, 0x82, 0x7e, 0x52, 0x90, 0x6d, 0xef }}