I<Usually you don't have to include it explicitly because
it's already included by ssl.h>.
-=item B<ssl23.h>
-
-That's the sub header file dealing with the combined use of different
-protocol version.
-I<Usually you don't have to include it explicitly because
-it's already included by ssl.h>.
-
=item B<tls1.h>
That's the sub header file dealing with the TLSv1 protocol only.