diff --git a/sys/inherit_list.h b/sys/inherit_list.h
new file mode 100644
index 0000000..626b1e9
--- /dev/null
+++ b/sys/inherit_list.h
@@ -0,0 +1,10 @@
+#ifndef LPC_INHERIT_LIST_H
+#define LPC_INHERIT_LIST_H
+
+/* Return value flag types for inherit_list() */
+
+#define INHLIST_FLAT         0x00
+#define INHLIST_TREE         0x01
+#define INHLIST_TAG_VIRTUAL  0x02
+
+#endif /* LPC_INHERIT_LIST_H */