  Let $G$ be a classical group over a non-Archimedean local field of odd
residual characteristic. Using recent work of S. Stevens, we define a certain
kind of semisimple stratum, called good, and show that it provides a simple
type in $G$ which is an analogue of the simple type for $GL(N,F)$ defined by
Bushnell and Kutzko. Furthermore, we define a self-dual simple type in $G$.
