- * Return value: an #GSequenceIter pointing to the position of the first item
- * found equal to @data according to @cmp_func and @cmp_data.
+ * @cmp_func is called with two items of the @seq and @user_data.
+ * It should return 0 if the items are equal, a negative value if
+ * the first item comes before the second, and a positive value if
+ * the second item comes before the first.
+ *
+ * Return value: an #GSequenceIter pointing to the position of the
+ * first item found equal to @data according to @cmp_func and @cmp_data.