Index: uspace/lib/c/include/io/window.h
===================================================================
--- uspace/lib/c/include/io/window.h	(revision c072a292c19db94ad89515ef948e5fabe05dc9f1)
+++ uspace/lib/c/include/io/window.h	(revision 15fbe6acd40fcb3e688db865b931ed04c43f0548)
@@ -42,4 +42,10 @@
 #include <io/kbd_event.h>
 #include <io/pos_event.h>
+
+typedef enum {
+	WINDOW_MAIN = 1,
+	WINDOW_DECORATED = 2,
+	WINDOW_RESIZEABLE = 4
+} window_flags_t;
 
 typedef enum {
@@ -108,5 +114,6 @@
 } window_event_t;
 
-extern int win_register(async_sess_t *, service_id_t *, service_id_t *);
+extern int win_register(async_sess_t *, window_flags_t, service_id_t *,
+    service_id_t *);
 
 extern int win_get_event(async_sess_t *, window_event_t *);