diff --git a/sys/thing/properties.h b/sys/thing/properties.h
index be7a6cd..77ec0d0 100644
--- a/sys/thing/properties.h
+++ b/sys/thing/properties.h
@@ -7,11 +7,12 @@
 #ifndef __THING_PROPERTIES_H__
 #define __THING_PROPERTIES_H__
 
-// Flags indexing <prop> and they are used as well for Set() calls
+// Type Flags indexing <prop> and they are used as well for Set() calls
 #define F_VALUE         0
 #define F_MODE          1
 #define F_SET_METHOD    2
 #define F_QUERY_METHOD  3
+#define F_PROP_ENTRIES  4 // how many entries in <prop> mapping?
 
 // The following are used as type flags for Set(), but they do not index
 // <prop>, therfore they have a negative sign.
@@ -20,11 +21,11 @@
 // automatically
 #define F_SET_MAPPER    -F_SET_METHOD
 // Flags for Set() to modify/manipulate F_MODE of a property in bit-wise
-// manner
-#define F_MODE_AS       4
-#define F_MODE_AD       5
+// manner (but are themselves not bitwise of course!).
+#define F_MODE_AS       -400
+#define F_MODE_AD       -500
 
-// mode flags for Properties
+// and from here the mode flags for Properties
 #define SAVE            64
 #define PROTECTED       128  // only this_object() can change the values
 #define SECURED         256  // like PROTECTED, but never resetable