A novel generalization of Clifford's classical point-circle   configuration. Geometric interpretation of the quaternionic discrete   Schwarzian KP equation
  The algebraic and geometric properties of a novel generalization of Clifford's classical C4 point-circle configuration are analysed. A connection with the integrable quaternionic discrete Schwarzian Kadomtsev-Petviashvili equation is revealed. 
W.K. Schief and B.G. Konopelchenko