@c gnutls_alpn_flags_t
@table @code
@item GNUTLS_@-ALPN_@-MANDATORY
Require ALPN negotiation. The connection will be
aborted if no matching ALPN protocol is found.
@item GNUTLS_@-ALPN_@-SERVER_@-PRECEDENCE
The choices set by the server
will take precedence over the client's.
@end table