diff --git a/ChangeLog b/ChangeLog
index c362fb978d..e00341490e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -3,6 +3,8 @@
 	* app/core/gimpmarshal.list: reduced to the set of marshallers we
 	actually use.
 
+	* libgimpwidgets/gimpwidgetsmarshal.list: documented.
+
 2003-02-20  Michael Natterer  <mitch@gimp.org>
 
 	Reimplemented the undo history:
diff --git a/libgimpwidgets/gimpwidgetsmarshal.list b/libgimpwidgets/gimpwidgetsmarshal.list
index 38349c5729..c9248f19e2 100644
--- a/libgimpwidgets/gimpwidgetsmarshal.list
+++ b/libgimpwidgets/gimpwidgetsmarshal.list
@@ -1,3 +1,27 @@
-NONE:INT
-NONE:INT,INT
-NONE:POINTER,POINTER
+# see glib-genmarshal(1) for a detailed description of the file format,
+# possible parameter types are:
+#   VOID        indicates   no   return   type,  or  no  extra
+#               parameters. if VOID is used as  the  parameter
+#               list, no additional parameters may be present.
+#   BOOLEAN     for boolean types (gboolean)
+#   CHAR        for signed char types (gchar)
+#   UCHAR       for unsigned char types (guchar)
+#   INT         for signed integer types (gint)
+#   UINT        for unsigned integer types (guint)
+#   LONG        for signed long integer types (glong)
+#   ULONG       for unsigned long integer types (gulong)
+#   ENUM        for enumeration types (gint)
+#   FLAGS       for flag enumeration types (guint)
+#   FLOAT       for single-precision float types (gfloat)
+#   DOUBLE      for double-precision float types (gdouble)
+#   STRING      for string types (gchar*)
+#   BOXED       for boxed (anonymous but reference counted) types (GBoxed*)
+#   POINTER     for anonymous pointer types (gpointer)
+#   PARAM       for GParamSpec or derived types  (GParamSpec*)
+#   OBJECT      for GObject or derived types (GObject*)
+#   NONE        deprecated alias for VOID
+#   BOOL        deprecated alias for BOOLEAN
+
+VOID: INT
+VOID: INT, INT 
+VOID: POINTER, POINTER