PropertyHandle :: GetUserTypeID - - internal feature (not documented)
Return value: Position in collection ( int32 )
The position of an instance in a collection depends on the selected index. if the collection is unsorted the position is the only way for accessing the instance.
For sorted collections the position is determined according to the instance key. If is a contradiction between position and key value the position will be ignored.
Special positions are
CUR_INSTANCE (-1) refers to the currently selected instance. If no instance is selected it refers to the first instance.
FIRST_INSTANCE (0) refers to the first instance in a collection according to the selected index (sort order).
FIRST_INSTANCE (0x7fffffff) refers to the last instance in a collection according to the selected index (sort order).