The document discusses Grice's Cooperative Principle, which states that communication involves cooperation between participants to establish meaning. It consists of four maxims: quality, quantity, relation, and manner. Conversational implicatures refer to implied meanings derived through inference rather than what is literally stated. Speakers can implicate additional meanings by observing or flouting the maxims, such as providing less information than required to imply uncertainty. The document provides examples of how speakers can flout different maxims to convey extra meanings.