1. A content search system for determining whether an input string matches one or more rules, the content search system comprising: a hardware-implemented parser, having an input to receive the input string, to extract one or more selected portions of the input string to form a filtered input string and to generate a rule select signal in response to the selected portions of the input string; a rules database for storing a plurality of sets of rules; a hardware-implemented normalizer engine comprising an input configured to receive the filtered input string from the parser; a decoder configured to decode encoded text in the filtered input string and provide an un-encoded filtered input string as an output; a plurality of transducers, each transducer of the plurality of transducers configured to receive the un-encoded filtered input string, and configured to perform a different field-specific normalization operation; and an output configured to provide a normalized un-encoded filtered input string; and a search engine, having an input configured to receive the normalized un-encoded filtered input string, coupled to the rules database, configured to compare the normalized un-encoded filtered input string with a selected set of rules selected in response to the rule select signal; wherein the plurality of transducers are connected in series between the decoder and the search engine; wherein each transducer of the plurality of transducers is configured to be activated or deactivated in response to a signal from the parser.