The following features have been removed.  They are not "missing".
Please do not report their absence as a bug.

* Translation tables (digraphs)
* Menus
* External history file support
* ircserv (ircio)
* ircflush
* Mail support giving you From and Subject lines of each email
* External encryption program support
* DAEMON_UID and anonymous telnet client support
* DCC TALK
* Support for crufty old SVR2 and 4.3BSD systems (HPUX7/8/9, ESIX, RT, etc)

Thanks.