@c gnutls_ext_flags_t
@table @code
@item GNUTLS_@-EXT_@-FLAG_@-OVERRIDE_@-INTERNAL
If specified the extension registered will override the internal; this does not work with extensions existing prior to 3.6.0.
@item GNUTLS_@-EXT_@-FLAG_@-CLIENT_@-HELLO
This extension can be present in a client hello
@item GNUTLS_@-EXT_@-FLAG_@-TLS12_@-SERVER_@-HELLO
This extension can be present in a TLS1.2 or earlier server hello
@item GNUTLS_@-EXT_@-FLAG_@-TLS13_@-SERVER_@-HELLO
This extension can be present in a TLS1.3 server hello
@item GNUTLS_@-EXT_@-FLAG_@-EE
This extension can be present in encrypted extensions message
@item GNUTLS_@-EXT_@-FLAG_@-HRR
This extension can be present in hello retry request message
@item GNUTLS_@-EXT_@-FLAG_@-IGNORE_@-CLIENT_@-REQUEST
When flag is present, this extension will be send even if the client didn't advertise it. An extension of this type is the Cookie TLS1.3 extension.
@item GNUTLS_@-EXT_@-FLAG_@-TLS
This extension can be present under TLS; otherwise ignored.
@item GNUTLS_@-EXT_@-FLAG_@-DTLS
This extension can be present under DTLS; otherwise ignored.
@end table