diff -ruN scummvm-20090303-orig/graphics/iff.h scummvm-20090303/graphics/iff.h
--- scummvm-20090303-orig/graphics/iff.h	2008-04-01 01:19:52.000000000 +0100
+++ scummvm-20090303/graphics/iff.h	2009-03-03 20:35:54.000000000 +0000
@@ -22,6 +22,12 @@
  * $Id: iff.h 30667 2008-01-28 00:14:17Z jvprat $
  */
 
+/**
+ * Bitmap decoder used in engines:
+ *  - parallaction
+ *  - saga
+ */
 
 #ifndef GRAPHICS_IFF_H
 #define GRAPHICS_IFF_H
diff -ruN scummvm-20090303-orig/graphics/video/dxa_player.h scummvm-20090303/graphics/video/dxa_player.h
--- scummvm-20090303-orig/graphics/video/dxa_player.h	2009-01-11 07:05:13.000000000 +0000
+++ scummvm-20090303/graphics/video/dxa_player.h	2009-03-03 20:29:18.000000000 +0000
@@ -23,6 +23,13 @@
  *
  */
 
+/**
+ * Video decoder used in engines:
+ *  - agos
+ *  - sword1
+ *  - sword2
+ */
+
 #ifndef GRAPHICS_VIDEO_DXA_PLAYER_H
 #define GRAPHICS_VIDEO_DXA_PLAYER_H
 
diff -ruN scummvm-20090303-orig/graphics/video/flic_player.h scummvm-20090303/graphics/video/flic_player.h
--- scummvm-20090303-orig/graphics/video/flic_player.h	2009-01-27 07:05:11.000000000 +0000
+++ scummvm-20090303/graphics/video/flic_player.h	2009-03-03 20:31:51.000000000 +0000
@@ -23,6 +23,12 @@
  *
  */
 
+/**
+ * Video decoder used in engines:
+ *  - tucker
+ */
+
 #ifndef GRAPHICS_VIDEO_FLICPLAYER_H
 #define GRAPHICS_VIDEO_FLICPLAYER_H
 
diff -ruN scummvm-20090303-orig/graphics/video/smk_player.h scummvm-20090303/graphics/video/smk_player.h
--- scummvm-20090303-orig/graphics/video/smk_player.h	2009-01-11 07:05:13.000000000 +0000
+++ scummvm-20090303/graphics/video/smk_player.h	2009-03-03 20:30:30.000000000 +0000
@@ -23,6 +23,15 @@
  *
  */
 
+/**
+ * Video decoder used in engines:
+ *  - agos
+ *  - saga
+ *  - scumm (he)
+ *  - sword1
+ *  - sword2
+ */
+
 // Based on http://wiki.multimedia.cx/index.php?title=Smacker
 // and the FFmpeg Smacker decoder (libavcodec/smacker.c), revision 16143
 // http://svn.ffmpeg.org/ffmpeg/trunk/libavcodec/smacker.c?revision=16143&view=markup
diff -ruN scummvm-20090303-orig/sound/adpcm.h scummvm-20090303/sound/adpcm.h
--- scummvm-20090303-orig/sound/adpcm.h	2009-01-28 07:05:08.000000000 +0000
+++ scummvm-20090303/sound/adpcm.h	2009-03-03 20:37:34.000000000 +0000
@@ -23,6 +23,14 @@
  *
  */
 
+/**
+ * Sound decoder used in engines:
+ *  - agos
+ *  - saga
+ *  - scumm
+ *  - tinsel
+ */
+
 #ifndef SOUND_ADPCM_H
 #define SOUND_ADPCM_H
 
diff -ruN scummvm-20090303-orig/sound/aiff.h scummvm-20090303/sound/aiff.h
--- scummvm-20090303-orig/sound/aiff.h	2008-04-01 01:19:39.000000000 +0100
+++ scummvm-20090303/sound/aiff.h	2009-03-03 20:37:57.000000000 +0000
@@ -23,6 +23,12 @@
  *
  */
 
+/**
+ * Sound decoder used in engines:
+ *  - saga
+ *  - sword1
+ */
+
 #ifndef SOUND_AIFF_H
 #define SOUND_AIFF_H
 
diff -ruN scummvm-20090303-orig/sound/flac.h scummvm-20090303/sound/flac.h
--- scummvm-20090303-orig/sound/flac.h	2008-09-05 09:05:12.000000000 +0100
+++ scummvm-20090303/sound/flac.h	2009-03-03 20:34:00.000000000 +0000
@@ -23,6 +23,20 @@
  *
  */
 
+/**
+ * Sound decoder used in engines:
+ *  - agos
+ *  - kyra
+ *  - m4
+ *  - queen
+ *  - saga
+ *  - scumm
+ *  - sword1
+ *  - sword2
+ *  - touche
+ *  - tucker
+ */
+
 #ifndef SOUND_FLAC_H
 #define SOUND_FLAC_H
 
diff -ruN scummvm-20090303-orig/sound/fmopl.h scummvm-20090303/sound/fmopl.h
--- scummvm-20090303-orig/sound/fmopl.h	2009-02-16 08:05:16.000000000 +0000
+++ scummvm-20090303/sound/fmopl.h	2009-03-03 20:39:17.000000000 +0000
@@ -25,6 +25,17 @@
  * Tatsuyuki Satoh. Included from LGPL'ed AdPlug.
  */
 
+/**
+ * Sound decoder used in engines:
+ *  - cine
+ *  - gob
+ *  - igor
+ *  - kyra
+ *  - queen
+ *  - sci
+ *  - sky
+ */
 
 #ifndef SOUND_FMOPL_H
 #define SOUND_FMOPL_H
diff -ruN scummvm-20090303-orig/sound/iff.h scummvm-20090303/sound/iff.h
--- scummvm-20090303-orig/sound/iff.h	2008-04-01 01:19:39.000000000 +0100
+++ scummvm-20090303/sound/iff.h	2009-03-03 20:40:15.000000000 +0000
@@ -23,6 +23,11 @@
  *
  */
 
+/**
+ * Sound decoder used in engines:
+ *  - parallaction
+ */
+
 #ifndef SOUND_IFF_H
 #define SOUND_IFF_H
 
diff -ruN scummvm-20090303-orig/sound/mods/infogrames.h scummvm-20090303/sound/mods/infogrames.h
--- scummvm-20090303-orig/sound/mods/infogrames.h	2008-09-06 09:05:11.000000000 +0100
+++ scummvm-20090303/sound/mods/infogrames.h	2009-03-03 20:43:59.000000000 +0000
@@ -23,6 +23,11 @@
  *
  */
 
+/**
+ * Sound decoder used in engines:
+ *  - gob
+ */
+
 #ifndef SOUND_MODS_INFOGRAMES_H
 #define SOUND_MODS_INFOGRAMES_H
 
diff -ruN scummvm-20090303-orig/sound/mods/protracker.h scummvm-20090303/sound/mods/protracker.h
--- scummvm-20090303-orig/sound/mods/protracker.h	2008-04-01 01:19:21.000000000 +0100
+++ scummvm-20090303/sound/mods/protracker.h	2009-03-03 20:44:23.000000000 +0000
@@ -23,6 +23,12 @@
  *
  */
 
+/**
+ * Sound decoder used in engines:
+ *  - agos
+ *  - parallaction
+ */
+
 #ifndef SOUND_MODS_PROTRACKER_H
 #define SOUND_MODS_PROTRACKER_H
 
diff -ruN scummvm-20090303-orig/sound/mods/rjp1.h scummvm-20090303/sound/mods/rjp1.h
--- scummvm-20090303-orig/sound/mods/rjp1.h	2008-04-01 01:19:21.000000000 +0100
+++ scummvm-20090303/sound/mods/rjp1.h	2009-03-03 20:43:00.000000000 +0000
@@ -23,6 +23,11 @@
  *
  */
 
+/**
+ * Sound decoder used in engines:
+ *  - queen
+ */
+
 #ifndef SOUND_MODS_RJP1_H
 #define SOUND_MODS_RJP1_H
 
diff -ruN scummvm-20090303-orig/sound/mods/soundfx.h scummvm-20090303/sound/mods/soundfx.h
--- scummvm-20090303-orig/sound/mods/soundfx.h	2008-04-01 01:19:21.000000000 +0100
+++ scummvm-20090303/sound/mods/soundfx.h	2009-03-03 20:42:38.000000000 +0000
@@ -21,6 +21,11 @@
  *
  */
 
+/**
+ * Sound decoder used in engines:
+ *  - cine
+ */
+
 #ifndef SOUND_MODS_SOUNDFX_H
 #define SOUND_MODS_SOUNDFX_H
 
diff -ruN scummvm-20090303-orig/sound/mp3.h scummvm-20090303/sound/mp3.h
--- scummvm-20090303-orig/sound/mp3.h	2008-09-05 09:05:12.000000000 +0100
+++ scummvm-20090303/sound/mp3.h	2009-03-03 20:36:53.000000000 +0000
@@ -23,6 +23,20 @@
  *
  */
 
+/**
+ * Sound decoder used in engines:
+ *  - agos
+ *  - kyra
+ *  - m4
+ *  - queen
+ *  - saga
+ *  - scumm
+ *  - sword1
+ *  - sword2
+ *  - touche
+ *  - tucker
+ */
+
 #ifndef SOUND_MP3_H
 #define SOUND_MP3_H
 
diff -ruN scummvm-20090303-orig/sound/voc.h scummvm-20090303/sound/voc.h
--- scummvm-20090303-orig/sound/voc.h	2009-01-27 07:05:10.000000000 +0000
+++ scummvm-20090303/sound/voc.h	2009-03-03 20:41:14.000000000 +0000
@@ -23,6 +23,18 @@
  *
  */
 
+/**
+ * Sound decoder used in engines:
+ *  - agos
+ *  - drascula
+ *  - igor
+ *  - kyra
+ *  - made
+ *  - saga
+ *  - scumm
+ *  - touche
+ */
+
 #ifndef SOUND_VOC_H
 #define SOUND_VOC_H
 
diff -ruN scummvm-20090303-orig/sound/vorbis.h scummvm-20090303/sound/vorbis.h
--- scummvm-20090303-orig/sound/vorbis.h	2008-09-05 09:05:12.000000000 +0100
+++ scummvm-20090303/sound/vorbis.h	2009-03-03 20:36:41.000000000 +0000
@@ -23,6 +23,20 @@
  *
  */
 
+/**
+ * Sound decoder used in engines:
+ *  - agos
+ *  - kyra
+ *  - m4
+ *  - queen
+ *  - saga
+ *  - scumm
+ *  - sword1
+ *  - sword2
+ *  - touche
+ *  - tucker
+ */
+
 #ifndef SOUND_VORBIS_H
 #define SOUND_VORBIS_H
 
diff -ruN scummvm-20090303-orig/sound/wave.h scummvm-20090303/sound/wave.h
--- scummvm-20090303-orig/sound/wave.h	2009-01-27 07:05:10.000000000 +0000
+++ scummvm-20090303/sound/wave.h	2009-03-03 20:42:07.000000000 +0000
@@ -23,6 +23,17 @@
  *
  */
 
+/**
+ * Sound decoder used in engines:
+ *  - agos
+ *  - gob
+ *  - saga
+ *  - scumm
+ *  - sword1
+ *  - sword2
+ *  - tucker
+ */
+
 #ifndef SOUND_WAVE_H
 #define SOUND_WAVE_H