diff --git a/MdeModulePkg/Core/Dxe/Mem/Imem.h b/MdeModulePkg/Core/Dxe/Mem/Imem.h
index a76ae2fe67..6f4065e3b8 100644
--- a/MdeModulePkg/Core/Dxe/Mem/Imem.h
+++ b/MdeModulePkg/Core/Dxe/Mem/Imem.h
@@ -1,7 +1,7 @@
 /** @file
   Data structure and functions to allocate and free memory space.
 
-Copyright (c) 2006 - 2015, Intel Corporation. All rights reserved.<BR>
+Copyright (c) 2006 - 2016, Intel Corporation. All rights reserved.<BR>
 This program and the accompanying materials
 are licensed and made available under the terms and conditions of the BSD License
 which accompanies this distribution.  The full text of the license may be found at
@@ -19,7 +19,7 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
 // +---------------------------------------------------+
 // | 0..(EfiMaxMemoryType - 1)    - Normal memory type |
 // +---------------------------------------------------+
-// | EfiMaxMemoryType..0x6FFFFFFF - Ilegal             |
+// | EfiMaxMemoryType..0x6FFFFFFF - Invalid            |
 // +---------------------------------------------------+
 // | 0x70000000..0x7FFFFFFF       - OEM reserved       |
 // +---------------------------------------------------+
diff --git a/MdeModulePkg/Core/Dxe/Mem/Pool.c b/MdeModulePkg/Core/Dxe/Mem/Pool.c
index ad9a85feaf..528c8e8ce9 100644
--- a/MdeModulePkg/Core/Dxe/Mem/Pool.c
+++ b/MdeModulePkg/Core/Dxe/Mem/Pool.c
@@ -197,8 +197,9 @@ LookupPoolHead (
   @param  Buffer                 The address to return a pointer to the allocated
                                  pool
 
-  @retval EFI_INVALID_PARAMETER  PoolType not valid or Buffer is NULL. 
-                                 PoolType was EfiPersistentMemory.
+  @retval EFI_INVALID_PARAMETER  Buffer is NULL.
+                                 PoolType is in the range EfiMaxMemoryType..0x6FFFFFFF.
+                                 PoolType is EfiPersistentMemory.
   @retval EFI_OUT_OF_RESOURCES   Size exceeds max pool size or allocation failed.
   @retval EFI_SUCCESS            Pool successfully allocated.
 
@@ -256,7 +257,9 @@ CoreInternalAllocatePool (
   @param  Buffer                 The address to return a pointer to the allocated
                                  pool
 
-  @retval EFI_INVALID_PARAMETER  PoolType not valid or Buffer is NULL. 
+  @retval EFI_INVALID_PARAMETER  Buffer is NULL.
+                                 PoolType is in the range EfiMaxMemoryType..0x6FFFFFFF.
+                                 PoolType is EfiPersistentMemory.
   @retval EFI_OUT_OF_RESOURCES   Size exceeds max pool size or allocation failed.
   @retval EFI_SUCCESS            Pool successfully allocated.