Thanks to Cahata for the idea!
#define RPL_CREATED_MSG "003 %s :This server has been started %s"
#define RPL_MYINFO_MSG "004 %s %s ngircd-%s %s %s"
#define RPL_ISUPPORT1_MSG "005 %s RFC2812 IRCD=ngIRCd CASEMAPPING=ascii PREFIX=(ov)@+ CHANTYPES=#&+ CHANMODES=beI,k,l,imnOPRstz CHANLIMIT=#&+:%d :are supported on this server"
-#define RPL_ISUPPORT2_MSG "005 %s CHANNELLEN=%d NICKLEN=%d TOPICLEN=%d AWAYLEN=%d KICKLEN=%d MODES=%d MAXLIST=beI:%d PENALTY :are supported on this server"
+#define RPL_ISUPPORT2_MSG "005 %s CHANNELLEN=%d NICKLEN=%d TOPICLEN=%d AWAYLEN=%d KICKLEN=%d MODES=%d MAXLIST=beI:%d EXCEPTS=e INVEX=I PENALTY :are supported on this server"
#define RPL_TRACELINK_MSG "200 %s Link %s-%s %s %s V%s %ld %d %d"
#define RPL_TRACEOPERATOR_MSG "204 %s Oper 2 :%s"