Comment on 'Note on generalization of Shannon theorem and inequality'

K work Sau Fa (1998 J. Phys. A: Math. Gen. 318159) has shown an inequality 'S(AB) less than or equal to S(A) + S(B) + (1 - q)S(A)S(B)' for two interacting systems A and B. A typical example of S(A) is the Tsallis entropy as stated in his paper. However, there exist many counterexamples to the above inequality. The reason leading to the incorrect result is also presented.