diff --git a/src/hb-buffer.h b/src/hb-buffer.h
index 9b72383..062c4e7 100644
--- a/src/hb-buffer.h
+++ b/src/hb-buffer.h
@@ -58,7 +58,7 @@
  *           hb_buffer_set_cluster_level() allow selecting more fine-grained
  *           cluster handling.
  *
- * The #hb_glyph_info_t is the structure that holds informations about the
+ * The #hb_glyph_info_t is the structure that holds information about the
  * glyphs and their relation to input text.
  *
  */
@@ -98,7 +98,16 @@
   hb_var_int_t   var;
 } hb_glyph_position_t;
 
-
+/**
+ * hb_segment_properties_t:
+ * @direction: the #hb_direction_t of the buffer, see hb_buffer_set_direction().
+ * @script: the #hb_script_t of the buffer, see hb_buffer_set_script().
+ * @language: the #hb_language_t of the buffer, see hb_buffer_set_language().
+ *
+ * The structure that holds various text properties of an #hb_buffer_t. Can be
+ * set and retrieved using hb_buffer_set_segment_properties() and
+ * hb_buffer_get_segment_properties(), respectively.
+ */
 typedef struct hb_segment_properties_t {
   hb_direction_t  direction;
   hb_script_t     script;
@@ -123,8 +132,11 @@
 
 
 
-/*
- * hb_buffer_t
+/**
+ * hb_buffer_t:
+ *
+ * The main structure holding the input text and its properties before shaping,
+ * and output glyphs and their information after shaping.
  */
 
 typedef struct hb_buffer_t hb_buffer_t;
@@ -262,10 +274,16 @@
 HB_EXTERN hb_buffer_cluster_level_t
 hb_buffer_get_cluster_level (hb_buffer_t *buffer);
 
+/**
+ * HB_BUFFER_REPLACEMENT_CODEPOINT_DEFAULT:
+ *
+ * The default code point for replacing invalid characters in a given encoding.
+ * Set to U+FFFD REPLACEMENT CHARACTER.
+ *
+ * Since: 0.9.31
+ */
 #define HB_BUFFER_REPLACEMENT_CODEPOINT_DEFAULT 0xFFFDu
 
-/* Sets codepoint used to replace invalid UTF-8/16/32 entries.
- * Default is 0xFFFDu. */
 HB_EXTERN void
 hb_buffer_set_replacement_codepoint (hb_buffer_t    *buffer,
 				     hb_codepoint_t  replacement);
@@ -274,22 +292,17 @@
 hb_buffer_get_replacement_codepoint (hb_buffer_t    *buffer);
 
 
-/* Resets the buffer.  Afterwards it's as if it was just created,
- * except that it has a larger buffer allocated perhaps... */
 HB_EXTERN void
 hb_buffer_reset (hb_buffer_t *buffer);
 
-/* Like reset, but does NOT clear unicode_funcs and replacement_codepoint. */
 HB_EXTERN void
 hb_buffer_clear_contents (hb_buffer_t *buffer);
 
-/* Returns false if allocation failed */
 HB_EXTERN hb_bool_t
 hb_buffer_pre_allocate (hb_buffer_t  *buffer,
 		        unsigned int  size);
 
 
-/* Returns false if allocation has failed before */
 HB_EXTERN hb_bool_t
 hb_buffer_allocation_successful (hb_buffer_t  *buffer);
 
@@ -332,7 +345,6 @@
 		     unsigned int    item_offset,
 		     int             item_length);
 
-/* Allows only access to first 256 Unicode codepoints. */
 HB_EXTERN void
 hb_buffer_add_latin1 (hb_buffer_t   *buffer,
 		      const uint8_t *text,
@@ -340,7 +352,6 @@
 		      unsigned int   item_offset,
 		      int            item_length);
 
-/* Like add_utf32 but does NOT check for invalid Unicode codepoints. */
 HB_EXTERN void
 hb_buffer_add_codepoints (hb_buffer_t          *buffer,
 			  const hb_codepoint_t *text,
@@ -349,31 +360,24 @@
 			  int                   item_length);
 
 
-/* Clears any new items added at the end */
 HB_EXTERN hb_bool_t
 hb_buffer_set_length (hb_buffer_t  *buffer,
 		      unsigned int  length);
 
-/* Return value valid as long as buffer not modified */
 HB_EXTERN unsigned int
 hb_buffer_get_length (hb_buffer_t *buffer);
 
 /* Getting glyphs out of the buffer */
 
-/* Return value valid as long as buffer not modified */
 HB_EXTERN hb_glyph_info_t *
 hb_buffer_get_glyph_infos (hb_buffer_t  *buffer,
                            unsigned int *length);
 
-/* Return value valid as long as buffer not modified */
 HB_EXTERN hb_glyph_position_t *
 hb_buffer_get_glyph_positions (hb_buffer_t  *buffer,
                                unsigned int *length);
 
 
-/* Reorders a glyph buffer to have canonical in-cluster glyph order / position.
- * The resulting clusters should behave identical to pre-reordering clusters.
- * NOTE: This has nothing to do with Unicode normalization. */
 HB_EXTERN void
 hb_buffer_normalize_glyphs (hb_buffer_t *buffer);
 
@@ -382,7 +386,16 @@
  * Serialize
  */
 
-/*
+/**
+ * hb_buffer_serialize_flags_t:
+ * @HB_BUFFER_SERIALIZE_FLAG_DEFAULT: serialize glyph names, clusters and positions.
+ * @HB_BUFFER_SERIALIZE_FLAG_NO_CLUSTERS: do not serialize glyph cluster.
+ * @HB_BUFFER_SERIALIZE_FLAG_NO_POSITIONS: do not serialize glyph position information.
+ * @HB_BUFFER_SERIALIZE_FLAG_NO_GLYPH_NAMES: do no serialize glyph name.
+ * @HB_BUFFER_SERIALIZE_FLAG_GLYPH_EXTENTS: serialize glyph extents.
+ *
+ * Flags that control what glyph information are serialized in hb_buffer_serialize_glyphs().
+ *
  * Since: 0.9.20
  */
 typedef enum { /*< flags >*/
@@ -393,13 +406,23 @@
   HB_BUFFER_SERIALIZE_FLAG_GLYPH_EXTENTS	= 0x00000008u
 } hb_buffer_serialize_flags_t;
 
+/**
+ * hb_buffer_serialize_format_t:
+ * @HB_BUFFER_SERIALIZE_FORMAT_TEXT: a human-readable, plain text format.
+ * @HB_BUFFER_SERIALIZE_FORMAT_JSON: a machine-readable JSON format.
+ * @HB_BUFFER_SERIALIZE_FORMAT_INVALID: invalid format. 
+ *
+ * The buffer serialization and de-serialization format used in
+ * hb_buffer_serialize_glyphs() and hb_buffer_deserialize_glyphs().
+ *
+ * Since: 0.9.2
+ */
 typedef enum {
   HB_BUFFER_SERIALIZE_FORMAT_TEXT	= HB_TAG('T','E','X','T'),
   HB_BUFFER_SERIALIZE_FORMAT_JSON	= HB_TAG('J','S','O','N'),
   HB_BUFFER_SERIALIZE_FORMAT_INVALID	= HB_TAG_NONE
 } hb_buffer_serialize_format_t;
 
-/* len=-1 means str is NUL-terminated. */
 HB_EXTERN hb_buffer_serialize_format_t
 hb_buffer_serialize_format_from_string (const char *str, int len);
 
@@ -409,24 +432,23 @@
 HB_EXTERN const char **
 hb_buffer_serialize_list_formats (void);
 
-/* Returns number of items, starting at start, that were serialized. */
 HB_EXTERN unsigned int
 hb_buffer_serialize_glyphs (hb_buffer_t *buffer,
 			    unsigned int start,
 			    unsigned int end,
 			    char *buf,
 			    unsigned int buf_size,
-			    unsigned int *buf_consumed, /* May be NULL */
-			    hb_font_t *font, /* May be NULL */
+			    unsigned int *buf_consumed,
+			    hb_font_t *font,
 			    hb_buffer_serialize_format_t format,
 			    hb_buffer_serialize_flags_t flags);
 
 HB_EXTERN hb_bool_t
 hb_buffer_deserialize_glyphs (hb_buffer_t *buffer,
 			      const char *buf,
-			      int buf_len, /* -1 means nul-terminated */
-			      const char **end_ptr, /* May be NULL */
-			      hb_font_t *font, /* May be NULL */
+			      int buf_len,
+			      const char **end_ptr,
+			      hb_font_t *font,
 			      hb_buffer_serialize_format_t format);