When you type /version you will often see something like this:
*** Server cs-pub.bu.edu: 2.8.21. AHiKmMptXY

Ever wondered what those funny chars mean after the version number? Well
here they are:

'A'	SENDQ_ALWAYS
'c'	CHROOTDIR
'C'	CMDLINE_CONFIG
'd'	DO_ID
'D'	DEBUGMODE
'e'	LOCOP_REHASH
'E'	OPER_REHASH
'f'	FOLLOW_IDENT_RFC
'F'	HIDE_FAKES
'g'	SUN_GSO_BUG
'G'	SHOW_GHOSTS
'H'	HUB
'i'	SHOW_INVISIBLE_LUSERS
'I'	NO_DEFAULT_INVISIBLE
'K'	OPER_KILL
'k'	LOCAL_KILL_ONLY
'L'	LEAST_IDLE
'm'	M4_PREPROC
'M'	IDLE_FROM_MSG
'N'	DELAY_NICKS
'p'	CRYPT_OPER_PASSWORD
'P'	CRYPT_LINK_PASSWORD
'N'	NPATH
'r'	LOCOP_RESTART
'R'	OPER_RESTART
's'	SECUNREG
'S'	ENABLE_SUMMON
't'	OPER_REMOTE
'T'	TRACE_STATS
'u'	IRCII_KLUDGE
'U'	ENABLE_USERS
'V'	VALLOC
'w'	NOWRITEALARM
'X'	UNIXPORT
'Y'	USE_SYSLOG
'8'	V28PlusOnly