+Use of these functions is deprecated. They have been replaced with TLS_method(),
+TLS_server_method() and TLS_client_method() respectively. New code should use
+those functions instead.
+
+=item DTLS_method(), DTLS_server_method(), DTLS_client_method()
+
+A DTLS connection established with those methods understands all
+supported DTLS protocols.
+Currently supported protocols are DTLS 1.0 and DTLS 1.2.
+
+=item DTLSv1_method(), DTLSv1_server_method(), DTLSv1_client_method()
+
+A DTLS connection established with these methods will only understand
+the DTLS 1.0 protocol.
+
+=item DTLSv1_2_method(), DTLSv1_2_server_method(), DTLSv1_2_client_method()
+
+A DTLS connection established with these methods will only understand
+the DTLS 1.2 protocol.
+
+=back
+
+TLS_method(), TLS_server_method(), TLS_client_method(), DTLS_method(),
+DTLS_server_method() and DTLS_client_method() are the version
+flexible methods.
+All other methods only support one specific protocol version.
+Use these methods instead of the other version specific methods.
+
+If you want to limit the supported protocols for the version flexible
+methods you can use SSL_CTX_set_min_proto_version(),
+SSL_set_min_proto_version(), SSL_CTX_set_max_proto_version() and
+SSL_set_max_proto_version() functions.
+They can also be limited using by using an option like SSL_OP_NO_SSLv3
+of the SSL_CTX_set_options() or SSL_set_options() functions, but
+that's not recommended.
+Using these functions it is possible to choose e.g. TLS_server_method()
+and be able to negotiate with all possible clients, but to only
+allow newer protocols like TLS 1.0, TLS 1.1 or TLS 1.2.
+
+SSL_CTX_new() initializes the list of ciphers, the session cache
+setting, the callbacks, the keys and certificates and the options
+to its default values.