BCH codes = large class of powerful random error correcting
cyclic codes.
Reed-Solomon (RS) codes = most important among the nonbinary
BCH codes.
A t-error correcting RS code with symbols from GF 
has the
following parameters:
A 
-ary (n,k) cyclic code is generated by a polynomial of degree
n-k with coefficients from GF , which is a factor of 
.