Remarks Towards the Classification of $RS_4^2(3)$-Transformations and   Algebraic Solutions of the Sixth Painlev\'e Equation
  We introduce a notion of the divisor type for rational functions and show that it can be effectively used for the classification of the deformations of dessins d'enfants related with the construction of the algebraic solutions of the sixth Painlev\'e equation via the method of $RS$-transformations. 
A. V. Kitaev