Spin models and their symmetry groups -- Subgroups and products of permissible groups -- Primitive and imprimitive permissible groups -- Regular groups -- Graph-theoretical constructions of permissible groups -- Tables of permissible groups -- Duality transformation's and dual models -- Pseudo-lattices -- Homogeneous spin models on Cayley branches with surface field -- Random spin models on Cayley branches with surface field -- Spin models on recursive bond graph sequences and fractals -- Gauge models on plaquette branches -- Critical exponents for systems on self-similar pseudo-lattices.