diff --git a/Import/GacUI.h b/Import/GacUI.h
index 6ecb198b..7dd2530d 100644
--- a/Import/GacUI.h
+++ b/Import/GacUI.h
@@ -6103,12 +6103,16 @@ Colorized Plain Text (model)
 
 #if defined VCZH_MSVC
 				/// <summary>Test if a wchar_t is the first character of a surrogate pair.</summary>
+				/// <param name="c">The character to test.</param>
+				/// <returns>Returns true if it is the first character of a surrogate pair.</returns>
 				inline bool UTF16SPFirst(wchar_t c)
 				{
 					return 0xD800 <= c && c < 0xDC00;
 				}
 
 				/// <summary>Test if a wchar_t is the second character of a surrogate pair.</summary>
+				/// <param name="c">The character to test.</param>
+				/// <returns>Returns true if it is the second character of a surrogate pair.</returns>
 				inline bool UTF16SPSecond(wchar_t c)
 				{
 					return 0xDC00 <= c && c < 0xDFFF;