+/**
+ * GtkCalendarDetailFunc:
+ * @calendar: a #GtkCalendar.
+ * @year: the year for which details are needed.
+ * @month: the month for which details are needed.
+ * @day: the day of @month for which details are needed.
+ * @user_data: the data passed with gtk_calendar_set_detail_func().
+ *
+ * This kind of functions provide Pango markup with detail information for the
+ * specified day. Examples for such details are holidays or appointments. The
+ * function returns %NULL when no information is available.
+ *
+ * Since: 2.14
+ *
+ * Return value: Newly allocated string with Pango markup with details
+ * for the specified day, or %NULL.
+ */
+typedef gchar* (*GtkCalendarDetailFunc) (GtkCalendar *calendar,
+ guint year,
+ guint month,
+ guint day,
+ gpointer user_data);
+