diff --git a/IntelFrameworkModulePkg/Library/PeiDxeDebugLibReportStatusCode/DebugLib.c b/IntelFrameworkModulePkg/Library/PeiDxeDebugLibReportStatusCode/DebugLib.c
index 6f4db10e88..58dd56bf4b 100644
--- a/IntelFrameworkModulePkg/Library/PeiDxeDebugLibReportStatusCode/DebugLib.c
+++ b/IntelFrameworkModulePkg/Library/PeiDxeDebugLibReportStatusCode/DebugLib.c
@@ -111,7 +111,7 @@ DebugPrint (
   DEBUG_PROPERTY_ASSERT_DEADLOOP_ENABLED bit of PcdDebugProperyMask is set then
   CpuDeadLoop() is called.  If neither of these bits are set, then this function
   returns immediately after the message is printed to the debug output device.
-  DebugAssert() must actively prevent recusrsion.  If DebugAssert() is called while
+  DebugAssert() must actively prevent recursion.  If DebugAssert() is called while
   processing another DebugAssert(), then DebugAssert() must return immediately.
 
   If FileName is NULL, then a <FileName> string of "(NULL) Filename" is printed.
diff --git a/MdePkg/Include/Library/DebugLib.h b/MdePkg/Include/Library/DebugLib.h
index 5f0c923fb4..828cd441cf 100644
--- a/MdePkg/Include/Library/DebugLib.h
+++ b/MdePkg/Include/Library/DebugLib.h
@@ -98,12 +98,12 @@ DebugPrint (
   DEBUG_PROPERTY_ASSERT_DEADLOOP_ENABLED bit of PcdDebugProperyMask is set then 
   CpuDeadLoop() is called.  If neither of these bits are set, then this function 
   returns immediately after the message is printed to the debug output device.
-  DebugAssert() must actively prevent recusrsion.  If DebugAssert() is called while
+  DebugAssert() must actively prevent recursion.  If DebugAssert() is called while
   processing another DebugAssert(), then DebugAssert() must return immediately.
 
-  If FileName is NULL, then a <FileName> string of ?NULL) Filename?is printed.
+  If FileName is NULL, then a <FileName> string of "(NULL) Filename" is printed.
 
-  If Description is NULL, then a <Description> string of ?NULL) Description?is printed.
+  If Description is NULL, then a <Description> string of "(NULL) Description" is printed.
 
   @param  FileName     Pointer to the name of the source file that generated the assert condition.
   @param  LineNumber   The line number in the source file that generated the assert condition
@@ -128,7 +128,7 @@ DebugAssert (
 
   If Buffer is NULL, then ASSERT().
 
-  If Length is greater than (MAX_ADDRESS ?Buffer + 1), then ASSERT(). 
+  If Length is greater than (MAX_ADDRESS -Buffer + 1), then ASSERT(). 
 
   @param   Buffer  Pointer to the target buffer to be filled with PcdDebugClearMemoryValue.
   @param   Length  Number of bytes in Buffer to fill with zeros PcdDebugClearMemoryValue. 
diff --git a/MdePkg/Include/Library/FvbServiceLib.h b/MdePkg/Include/Library/FvbServiceLib.h
index 1618716f44..88d2587ff6 100644
--- a/MdePkg/Include/Library/FvbServiceLib.h
+++ b/MdePkg/Include/Library/FvbServiceLib.h
@@ -12,8 +12,8 @@
 
 **/
 
-#ifndef __EDK_FVB_SERVICE_LIB_H__
-#define __EDK_FVB_SERVICE_LIB_H__
+#ifndef __FVB_SERVICE_LIB_H__
+#define __FVB_SERVICE_LIB_H__
 
 /**
   Reads specified number of bytes into a buffer from the specified block.
@@ -38,7 +38,7 @@ EfiFvbReadBlock (
   IN EFI_LBA                                      Lba,
   IN UINTN                                        Offset,
   IN OUT UINTN                                    *NumBytes,
-  IN UINT8                                        *Buffer
+  OUT UINT8                                        *Buffer
   );
 
 
diff --git a/MdePkg/Include/Library/HiiLib.h b/MdePkg/Include/Library/HiiLib.h
index 012a7b8052..33bcf30a21 100644
--- a/MdePkg/Include/Library/HiiLib.h
+++ b/MdePkg/Include/Library/HiiLib.h
@@ -173,7 +173,6 @@ HiiLibSetString (
   @retval EFI_NOT_FOUND          The string specified by StringId is not available.
   @retval EFI_BUFFER_TOO_SMALL   The buffer specified by StringLength is too small
                                  to hold the string.
-  @retval EFI_INVALID_PARAMETER  The String or StringSize was NULL.
 
 **/
 EFI_STATUS
diff --git a/MdePkg/Library/HiiLib/HiiLanguage.c b/MdePkg/Library/HiiLib/HiiLanguage.c
index 3d9a36d468..6948b2c331 100644
--- a/MdePkg/Library/HiiLib/HiiLanguage.c
+++ b/MdePkg/Library/HiiLib/HiiLanguage.c
@@ -84,6 +84,7 @@ HiiLibGetNextLanguage (
   CHAR8  *StringPtr;
 
   ASSERT (LangCode != NULL);
+  ASSERT (*LangCode != NULL);
   ASSERT (Lang != NULL);
 
   Index = 0;
diff --git a/MdePkg/Library/HiiLib/HiiString.c b/MdePkg/Library/HiiLib/HiiString.c
index 0d07ebc68a..c7d11a5761 100644
--- a/MdePkg/Library/HiiLib/HiiString.c
+++ b/MdePkg/Library/HiiLib/HiiString.c
@@ -230,7 +230,6 @@ Out:
   @retval EFI_NOT_FOUND          The string specified by StringId is not available.
   @retval EFI_BUFFER_TOO_SMALL   The buffer specified by StringLength is too small
                                  to hold the string.
-  @retval EFI_INVALID_PARAMETER  The String or StringSize was NULL.
 
 **/
 EFI_STATUS