select() or poll() on the underlying socket can be used to find out
when the TLS/SSL I/O function should be retried.
-Caveat: Any SSL I/O function can lead to either of
+Caveat: Any TLS/SSL I/O function can lead to either of
B<SSL_ERROR_WANT_READ> and B<SSL_ERROR_WANT_WRITE>, i.e. SSL_read()
may want to write data and SSL_write() may want to read data.
The operation did not complete because an application callback set by
SSL_CTX_set_client_cert_cb() has asked to be called again.
-The SSL I/O function should be called again later.
+The TLS/SSL I/O function should be called again later.
Details depend on the application.
=item SSL_ERROR_SYSCALL