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.
E is a factor for weight 1 (URL Weight bit) D is a factor for weight 2 (BodyWeight bit) C is a factor for weight 4 (TitleWeight bit) B is a factor for weight 8 (KeywordWeight bit) A is a factor for weight 16 (DescWeight bit)