As far as indexer uses bit OR operation for word weights when some word presents several time in the same document, it is possible at search time to detect word appearance in different document parts.
As far as indexer uses bit OR operation for word weights when some word presents several time in the same document, it is possible at search time to detect word appearance in different document parts. Word which appears only in the body will have 00000010 argegate weight (in binary notation). Word used in all document parts will have 00011111 aggregate weight.