The invention includes a method and apparatus for identifying a field name. The method includes a receiving a message comprising a plurality of fields, each field having a field name, and processing each of a plurality of characters of the received message for identifying the field names, where each character is processed using a plurality of associated arrays. A current character extracted from the received message id processed using a current array selected from the plurality of arrays. The current array used for processing the current character is adapted for identifying one of: (1) one of the plurality of field names or (2) an identifier for identifying a next array for processing the next character extracted from the received message.