When you type /version you will often see something like this:
bahamut-1.8(02). server aABCdFhistTY/HoS TS5ow-r[RELEASE] RPL1 NP[U]

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

The first set before the '/' are compile-time flags:
'a' config.h ANTI_SPAMBOT
'A' config.h ALWAYS_SEND_DURING_SPLIT
'B' config.h MAXBUFFERS
'C' config.h CMDLINE_CONFIG
'd' config.h DO_IDENTD
'D' config.h DEBUGMODE
'E' configure encryption support enabled
'F' config.h FLUD
'h' config.h SHOW_HEADERS
'i' config.h SHOW_INVISIBLE_LUSERS
'I' config.h NO_DEFAULT_INVISIBLE
'J' config.h NO_DEFAULT_JOINRATE
'M' configure module support enabled
'N' config.h DNS_DEBUG
'r' config.h DENY_SERVICES_MSGS
's' config.h SUPER_TARGETS_ONLY
't' config.h MSG_TARGET_LIMIT
'T' config.h THROTTLE_ENABLE
'u' config.h IRCII_KLUDGE
'Y' config.h USE_SYSLOG

The first set after the '/' are runtime flags:
'H' ircd.conf servtype = hub
'm' ircd.conf short_motd
'o' ircd.conf allow_split_ops
'p' ircd.conf crypt_oper_pass
'S' ircd.conf servtype = serviceshub
'w' ircd.conf wgmonhost/wgmonurl

The next part, 'TS5ow', is mostly historical.  The release tag is provided
after it.

If 'RPL#' shows up, oper hostmasking is enabled.  The number is the level:
 1  All +A users can see real IP
 2  Local +A users can see real IP
 3  Noone can see real IP (but it's still logged)

The last part, 'NP[]', contains network information hiding flags:
'A' config.h FORCE_EVERYONE_HIDDEN
'I' config.h ALLOW_HIDDEN_OPERS
'K' config.h HIDE_KILL_ORIGINS
'L' ircd.conf no show_links (hiding LINKS)
'M' config.h HIDE_SERVERMODE_ORIGINS
'N' config.h HIDE_NUMERIC_SOURCE
'O' config.h NO_USER_OPERTARGETED_COMMANDS
'P' config.h HIDE_SPLIT_SERVERS
'S' config.h NO_USER_STATS
'T' config.h NO_USER_TRACE
'U' config.h HIDEULINEDSERVS
'W' config.h NO_USER_SERVERNOTICES
