diff --git a/include/freetype/ftoutln.h b/include/freetype/ftoutln.h
index 06a3fa835..ef66d48c8 100644
--- a/include/freetype/ftoutln.h
+++ b/include/freetype/ftoutln.h
@@ -217,6 +217,10 @@ FT_BEGIN_HEADER
   /* <Return>                                                              */
   /*    FreeType error code.  0~means success.                             */
   /*                                                                       */
+  /* <Note>                                                                */
+  /*    An empty outline, or an outline with a single point only is also   */
+  /*    valid.                                                             */
+  /*                                                                       */
   FT_EXPORT( FT_Error )
   FT_Outline_Check( FT_Outline*  outline );
 
diff --git a/include/freetype/internal/ftmemory.h b/include/freetype/internal/ftmemory.h
index 8c06fc21a..fc33b2f50 100644
--- a/include/freetype/internal/ftmemory.h
+++ b/include/freetype/internal/ftmemory.h
@@ -108,10 +108,12 @@ extern "C++"
 
   /*
    *  The allocation functions return a pointer, and the error code
-   *  is written to through the `p_error' parameter.  See below for
-   *  for documentation.
+   *  is written to through the `p_error' parameter.
    */
 
+  /* The `q' variants of the functions below (`q' for `quick') don't fill */
+  /* the allocated or reallocated memory with zero bytes.                 */
+
   FT_BASE( FT_Pointer )
   ft_mem_alloc( FT_Memory  memory,
                 FT_Long    size,
@@ -143,6 +145,9 @@ extern "C++"
                const void*  P );
 
 
+  /* The `Q' variants of the macros below (`Q' for `quick') don't fill */
+  /* the allocated or reallocated memory with zero bytes.              */
+
 #define FT_MEM_ALLOC( ptr, size )                               \
           FT_ASSIGNP_INNER( ptr, ft_mem_alloc( memory,          \
                                                (FT_Long)(size), \