import of 2.10.12.07

[irc/quakenet/snircd.git] / doc / readme.features

Many of the old compile-time options are now configured through the
server configuration file, ircd.conf.  This file is intended to
document each of these features.  Logging, although also configured
through the use of Feature entries, is documented in doc/readme.log.  NOTE
THAT THESE NAMES ARE CASE SENSITIVE!  Values are not case sensitive
unless stated otherwise in the documentation for that feature.

DOMAINNAME
 * Type: string
 * Default: picked by ./configure from /etc/resolv.conf

This option allows you to specify what you consider to be "local."  It
is only used for statistics.  When you issue the IRC command /STATS w,
the server will respond with statistics of how many clients have been
connecting to your server in the last minute, hour and day.  It will
give these statistics for all connections (including the servers), all
clients (from anywhere) and also for clients whose hostname ends on
the domain you specify here.  So if you are an ISP and you want to
know what the client load from your own domain is, specify that domain
here.  If you are unsure what to do, then it isn't really important
what you give here, just don't give an empty string.  A good guess is
the last two parts of your own hostname (i.e., if your hostname is
foo.bar.nowhere.org, specify "nowhere.org").  Note that the string you
give should NOT start with a "." and you should not use quotes.

RELIABLE_CLOCK
 * Type: boolean
 * Default: FALSE

You should really ONLY specify "TRUE" here when your system clock is
stable and accurate at all times (within a few seconds).  If you are
running ntpdate on a regular basis, or an equivalent like xntpd, to
keep your system clock synchronized over the network, then you might
have an accurate clock.  However, this is not guaranteed; for example,
it is known that xntpd gives unstable results on Linux in some cases.
Note that an unstable clock is worse then an clock that has a constant
offset, because the servers attempt to correct for a constant offset,
but do not correct jumps of your system clock!  In general you SHOULD
be running ntpdate or equivalent AND make sure it works when you run a
production server on Undernet.  Otherwise leave your clock alone and
specify "FALSE" here.  If unsure specify "FALSE"!

BUFFERPOOL
 * Type: integer
 * Default: 27000000

This specifies the maximum amount of RAM that your server will
allocate for buffering sendQs.  Small leafs can use a value as little
as 1000000, while large HUBs need to specify a value as high as
20000000.  If you run out of memory, clients and/or servers are
dropped with the error "Buffer allocation error"; then you will have
to increase this number (and install more RAM if appropriate).  If you
want a more educated guess for this value then realize that any value
is good if you _really_ would rather drop servers and clients than
allocate more memory; this will be the case when there is the danger
you may run out of memory for other allocations.  Even if you run the
daemon on a dedicated machine, specifying all of the RAM you have is a
bad thing, because running out of memory is a lot worse than dropping
clients in a controlled way; if possible you should have memory left
for all the internal structures (channels, clients, ban lists, receive
buffers) at all times.  On average, clients seem to use 150 bytes of
sendQ, but at peak moments this can easily increase to 2032 bytes per
client (sendQs are allocated in chunks of 2032 bytes).  The maximum
possible amount that can be allocated for sendQs is the number of
connected clients times whatever you specified as the maximum sendQ in
your Class blocks in the ircd.conf file.  That value will likely be larger
then the amount of RAM you have.  The educated guess I talked about
earlier would be "number of clients" times * 2048 bytes + "size of
net.burst" * n, where "n" is 1 for leafs and up to 5 for HUBs.  The
"size of net.burst" is about 125 bytes per online client (on the whole
network).  For large HUBs with 4000 clients on a network with 30,000
users, this results in 27 Mb.  Leafs could use 12 Mb.  Of course you
can use less when you have less than 4000 local clients.  This value
is in bytes.

HAS_FERGUSON_FLUSHER
 * Type: boolean
 * Default: FALSE

If you have a server with a lot of resources available, this option
will cause the server to attempt to flush its internal buffers before
dropping clients during a net break.  Don't define this if you don't
know for certain; if you're not careful this can end up rebooting
FreeBSD boxes.  For more information, refer to freebsd.txt, also in
this directory.

CLIENT_FLOOD
 * Type: integer
 * Default: 1024

Currently, everything that a client sends to a server is read by the
server and stored in a buffer (the clients receive queue).  The server
will process messages from this queue one by one (running over all
clients each time).  When a client sends new messages faster they get
processed, and the size of its receive buffer reaches this value, the
client is dropped with the error "Excess flood."  A reasonable value
is 1024 bytes.  The maximum size is 8000 bytes.

SERVER_PORT
 * Type: integer
 * Default: 4400

When an IRC operator attempts a connect to another server, he or she
may not know which port the connect should go to.  In this server
version, that operator may use the special port 0, in which case the
server will take the port from the Connect block.  If no port is
specified in the Connect block, however, the port specified by this
option will be used instead.

NODEFAULTMOTD
 * Type: boolean
 * Default: TRUE

Every time a client connects to your server, the full Message of the
Day (as specified by the Motd blocks or by the file specified by the MPATH
option) is sent to the client.  The server sends the Message of the
Day even though many clients permit the user to ignore it.  Many users
never read the message of the day anyway, making it a huge waste of
bandwidth.  If you specify "TRUE" here, then the server won't send the
MOTD to the client by default; instead, it will only tell the client
when the MOTD was last changed, and give instructions on how to obtain
it by typing /MOTD.

MOTD_BANNER
 * Type: string
 * Default: NULL

If you enable NODEFAULTMOTD, this specifies a one-line banner to be sent
to the client in addition to the instructions mentioned above.

PROVIDER
 * Type: string
 * Default: NULL

This string as added to the 001 numeric prefixed with "via" before the nick.
It's used for providing promotional space to providers as per CFV-202

KILL_IPMISMATCH
 * Type: boolean
 * Default: FALSE

When a client connects to your server, the IP address of the client is
reverse-resolved to obtain a hostname.  Then that hostname is resolved
to an IP address and compared with the IP address of the client.  If
they don't match, the client will appear with the IP address instead
of the hostname, unless KILL_IPMISMATCH is "TRUE," in which case the
client is simply disconnected.

IDLE_FROM_MSG
 * Type: boolean
 * Default: TRUE

The IRC command WHOIS gives an idle time for clients.  If you want
this idle time to be set to zero only when the client sends a PRIVMSG,
then you should specify "TRUE" here.  If you specify "FALSE," then the
idle time will be nullified on all messages except the server
PING/PONG.

HUB
 * Type: boolean
 * Default: FALSE

All servers of an IRC "network" are connected in a "tree" (no loops).
Servers that are only connected to one other server (called the
"uplink") are called "leafs"; servers that are connected to more than
one other server are called HUBs.  If you specify "FALSE" here then
your server will prevent itself from accidentally connecting to two
servers at once, thus keeping servers in poor network locations from
routing traffic.  Note that on Undernet, all newly linked servers are
linked as leafs during their test phase, and should specify "FALSE"
here.

WALLOPS_OPER_ONLY
 * Type: boolean
 * Default: FALSE

Setting this option removes the ability for clients that are not IRC
operators to see wallops messages.

NODNS
 * Type: boolean
 * Default: FALSE

If you are playing with the server off-line, and no DNS is available,
then long delays occur before the server starts up because it tries to
resolve the name given in the General block (which usually isn't given
in /etc/hosts) and for each connecting client.  If you specify "TRUE"
here, then a DNS lookup will be done only for the real hostname, and
the server will not try to resolve clients that connect to
"localhost."  Note that other DNS lookups are still done for outbound
connections.

RANDOM_SEED
 * Type: string
 * Default: none

When a client connects, the server sends the client a "cookie,"
consisting of a random number.  The client must return the cookie to
the server verbatim.  This is done to prevent IP spoofing.  The cookie
is generated by a pseudorandom number generator included in ircd.
This generator must be seeded with a phrase that is kept secret, to
ensure that the numbers it generates are not easily guessed.  The
value given to RANDOM_SEED may be a string of any length.  It should
not contain any characters that are considered special by the
configuration file system, such as ":" or "#"; the string should be at
least 8 characters long, but longer strings are better.  The
RANDOM_SEED may not be retrieved online.

DEFAULT_LIST_PARAM
 * Type: string
 * Default: none

The LIST command takes a single optional argument.  If given, that
argument is either a channel or a filter.  If that argument is not
given, then by default, /LIST will list all channels on the network.
Needless to say, this can generate a large amount of data on large
networks with many channels, as well as chewing up a lot of CPU time.
Server administrators can therefore set a default filter to be applied
to the channel list if the optional argument to LIST is omitted.

NICKNAMEHISTORYLENGTH
 * Type: integer
 * Default: 800

This value specifies the length of the nick name history list, which
is used for /WHOWAS and some nickname chasing in /KILL and /KICK.  It
uses about 300 to 400 bytes per entry.  Note that at a net break, so
many client disappear that the whole "whowas" list is refreshed a few
times (unless you make it rather large).  A reasonable value is "total
number of clients" / 25.

HOST_HIDING
 * Type: boolean
 * Default: TRUE

This selects whether local users can set umode +x, thus allowing them
to hide their hostname if they have also registered with a channel
service (i.e. they have the ACCOUNT flag set).

HIDDEN_HOST
 * Type: string
 * Default: users.undernet.org

This selects the suffix for the hidden hostmask (see HOST_HIDING).

HIDDEN_IP
 * Type: string
 * Default: 127.0.0.1

This selects a fake IP to be shown on /USERIP and /WHO %i when the
target has a hidden host (see HOST_HIDING).

CONNEXIT_NOTICES
 * Type: boolean
 * Default: FALSE

This feature controls the generation of server notices when a user
connects to or disconnects from the server.  Enabling this feature may
have a performance impact.

KILLCHASETIMELIMIT
 * Type: integer
 * Default: 30

If a user changes his or her nickname just before an operator issues a
/KILL, the /KILL will be changed to follow the user the operator
intended to get.  This option specifies the time limit, in seconds,
for this nickname change; if the user changed his or her nickname more
than this many seconds ago, the /KILL will not be changed.  Don't
change this unless you really need to.

MAXCHANNELSPERUSER
 * Type: integer
 * Default: 10

This is the maximum number of channels a user can be in at a time.
The "mandatory" value on Undernet is currently 10.  Since it only
influences the local server when you decrease it, its up to you to
decide if you want to use a smaller value.  Do not use a larger value
however, because it DOES cost more memory and bandwidth on all other
servers when you allow users to join more channels simultaneously.
One of the most important reasons to choose a smaller value is the
fact that the "GUI" clients tend to stay on every channel they join
(they aren't bothered by flooding in other channels).  It DOES take
your bandwidth however to send all those messages for 10 different
channels to all your users.

AVBANLEN
 * Type: integer
 * Default: 40

This is the expected average ban mask length.  Leave it at 40.

MAXBANS
 * Type: integer
 * Default: 45

This is the maximum number of bans a user may set on a given channel.

MAXSILES
 * Type: integer
 * Default: 15

This is the maximum number of masks a user can silence at a time.  The
silence command allows users to filter messages directed at them from
certain users or domains, at the source server.  Increasing this
number allows users to use up more memory with inefficient use of the
command.  If you're not sure, don't change this.

HANGONGOODLINK
 * Type: integer
 * Default: 300

Often the net breaks for a short time and it is useful to try to
reestablish the same connection faster than CONNECTFREQUENCY would
allow, but to keep from trying again on a bad connection, we require
that the connection be open for a certain minimum time. The
recommended value is 300 seconds.

HANGONRETRYDELAY
 * Type: integer
 * Default: 10

When attempting to quickly reestablish a connection to a good link, we
give the net a few seconds to calm down. This time must be long enough
for the other end to also notice that the connection is broken. The
recommended value is 10 seconds.

CONNECTTIMEOUT
 * Type: integer
 * Default: 90

Number of seconds to wait for a connect(2) call to complete.  NOTE:
this must be at *LEAST* 10.  When a client connects, it has
CONNECTTIMEOUT - 10 seconds for its host to respond to an ident lookup
query and for a DNS lookup to complete. It is recommended that you not
change this value, but if you do, consider the fact that users whose
clients do not support NOSPOOF will have to type /QUOTE PING <big
number> before registration.

MAXIMUM_LINKS
 * Type: integer
 * Default: 1

This is the maximum number of links for the built-in client class 0.
Leave this value at 1.

PINGFREQUENCY
 * Type: integer
 * Default: 120

If the daemon doesn't receive anything from any of its links within
PINGFREQUENCY seconds, then the it will attempt to check for an active
link with a PING message.  If no reply is received within
(PINGFREQUENCY * 2) seconds, then the connection will be closed.  This
value may be overridden by a Class block in "ircd.conf" if the
connection's Client or Connect block in "ircd.conf" assigns a specific
class to the connection (recommended).

CONNECTFREQUENCY
 * Type: integer
 * Default: 600

This is the default frequency that the server attempts to reconnect
with its uplink server if it is set to auto connect to it. Note that
this value is overridden by a Class block in ircd.conf if the Connect
entries in ircd.conf assign a specific class to the connection.

DEFAULTMAXSENDQLENGTH
 * Type: integer
 * Default: 40000

This is the default value of the maximum sendQ length of connection
classes (see doc/example.conf for details on Class blocks).  You will
generally override this value in your "ircd.conf" with a Class block.

GLINEMAXUSERCOUNT
 * Type: integer
 * Default: 20

G-lines that affect too many users have to be set with a special
command, to prevent accidental G-lines of large blocks of users.  This
feature sets that particular threshold.

MPATH
 * Type: string
 * Default: "ircd.motd"

MPATH is the filename (relative to DPATH) or the full path of the
"Message of the Day" file.  The contents of this file will be sent to
every client that connects to the server, after registration.

RPATH
 * Type: string
 * Default: "remote.motd"

RPATH is the filename (relative to DPATH) or the full path of the
"Remote Message of the Day" file.  The contents of this file will be
sent to every remote client that issues a /MOTD <your server name>.
Only the first three lines are sent, so you might want to keep that in
mind while writing the file.

PPATH
 * Type: string
 * Default: "ircd.pid"

PPATH is the filename (relative to DPATH) or the full path of the
"PID" file.  It is used for storing the server's process ID so that a
ps(1) isn't necessary.

TOS_SERVER
 * Type: integer
 * Default: 0x08

This option is used to specify the type of service that will be
requested for connections to other servers.  The value may be given as
a hexadecimal integer.

TOS_CLIENT
 * Type: integer
 * Default: 0x08

This option is used to specify the type of service that will be
requested for connections to users.  The value may be given as a
hexadecimal integer.

POLLS_PER_LOOP
 * Type: integer
 * Default: 200

Some of the engines used by the event interface get a number of events
from the kernel at once.  Since the number retrieved can impact
performance, it can be tuned by modifying this value.  The engines
enforce a lower limit of 20.

CONFIG_OPERCMDS
 * Type: boolean
 * Default: FALSE

Since u2.10.11, several new oper-only features have been added that
involve changes to the server<->server protocol.  This configuration
option provides a single switch to prevent the use of these features
until the entire network has been upgraded.  It is not required that
all servers set this to "TRUE" in order for the features to be used,
as long as all servers are running u2.10.11 or above.

HIS_MAP
 * Type: boolean
 * Default: TRUE

As per UnderNet CFV-165, this removes /MAP from users.

HIS_SNOTICES
 * Type: boolean
 * Default: TRUE

As per UnderNet CFV-165, this removes server notices from users.

HIS_SNOTICES_OPER_ONLY
 * Type: boolean
 * Default: TRUE

As per UnderNet CFV-165, this removes server notices from users.

HIS_DEBUG_OPER_ONLY
 * Type: boolean
 * Default: TRUE

As per UnderNet CFV-165, this removes server wallops from users.

HIS_WALLOPS
 * Type: boolean
 * Default: TRUE

As per UnderNet CFV-165, this removes operator wallops from users.

HIS_LINKS
 * Type: boolean
 * Default: TRUE

As per UnderNet CFV-165, this removes /LINKS from users.

HIS_TRACE
 * Type: boolean
 * Default: TRUE

As per UnderNet CFV-165, this removes /TRACE from users.

HIS_STATS_a
 * Type: boolean
 * Default: TRUE

As per UnderNet CFV-165, this removes /STATS a from users.

HIS_STATS_c
 * Type: boolean
 * Default: TRUE

As per UnderNet CFV-165, this removes /STATS c from users.

HIS_STATS_d
 * Type: boolean
 * Default: TRUE

As per UnderNet CFV-165, this removes /STATS d from users.

HIS_STATS_e
 * Type: boolean
 * Default: TRUE

As per UnderNet CFV-165, this removes /STATS e from users.

HIS_STATS_f
 * Type: boolean
 * Default: TRUE

As per UnderNet CFV-165, this removes /STATS f from users.

HIS_STATS_g
 * Type: boolean
 * Default: TRUE

As per UnderNet CFV-165, this removes /STATS g from users.

HIS_STATS_i
 * Type: boolean
 * Default: TRUE

As per UnderNet CFV-165, this removes /STATS i from users.

HIS_STATS_j
 * Type: boolean
 * Default: TRUE

As per UnderNet CFV-165, this removes /STATS j from users.

HIS_STATS_J
 * Type: boolean
 * Default: TRUE

As per UnderNet CFV-165, this removes /STATS J from users.

HIS_STATS_k
 * Type: boolean
 * Default: TRUE

As per UnderNet CFV-165, this removes /STATS k from users.

HIS_STATS_l
 * Type: boolean
 * Default: TRUE

As per UnderNet CFV-165, this removes /STATS l from users.

HIS_STATS_L
 * Type: boolean
 * Default: TRUE

As per UnderNet CFV-165, this removes /STATS L from users.

HIS_STATS_M
 * Type: boolean
 * Default: TRUE

As per UnderNet CFV-165, this removes /STATS M from users.

HIS_STATS_m
 * Type: boolean
 * Default: TRUE

As per UnderNet CFV-165, this removes /STATS m from users.

HIS_STATS_o
 * Type: boolean
 * Default: TRUE

As per UnderNet CFV-165, this removes /STATS o from users.

HIS_STATS_p
 * Type: boolean
 * Default: TRUE

As per UnderNet CFV-165, this removes /STATS p from users.

HIS_STATS_q
 * Type: boolean
 * Default: TRUE

As per UnderNet CFV-165, this removes /STATS q from users.

HIS_STATS_r
 * Type: boolean
 * Default: TRUE

As per UnderNet CFV-165, this removes /STATS r from users.

HIS_STATS_R
 * Type: boolean
 * Default: TRUE

As per UnderNet CFV-165, this removes /STATS R from users.

HIS_STATS_t
 * Type: boolean
 * Default: TRUE

As per UnderNet CFV-165, this removes /STATS t from users.

HIS_STATS_T
 * Type: boolean
 * Default: TRUE

As per UnderNet CFV-165, this removes /STATS T from users.

HIS_STATS_u
 * Type: boolean
 * Default: FALSE

As per UnderNet CFV-165, this allows users to perform /STATS u.

HIS_STATS_U
 * Type: boolean
 * Default: TRUE

As per UnderNet CFV-165, this removes /STATS U from users.

HIS_STATS_v
 * Type: boolean
 * Default: TRUE

As per UnderNet CFV-165, this removes /STATS v from users.

HIS_STATS_w
 * Type: boolean
 * Default: FALSE

As per UnderNet CFV-165, this allows users to perform /STATS w.

HIS_STATS_x
 * Type: boolean
 * Default: TRUE

As per UnderNet CFV-165, this removes /STATS x from users.

HIS_STATS_y
 * Type: boolean
 * Default: TRUE

As per UnderNet CFV-165, this removes /STATS y from users.

HIS_STATS_z
 * Type: boolean
 * Default: TRUE

As per UnderNet CFV-165, this removes /STATS z from users.

HIS_STATS_IAUTH
 * Type: boolean
 * Default: TRUE

As per UnderNet CFV-165, this disables /STATS IAUTH and
/STATS IAUTHCONF from users.

HIS_WHOIS_SERVERNAME
 * Type: boolean
 * Default: TRUE

As per UnderNet CFV-165, this removes server names in replies to /WHOIS.

HIS_WHOIS_IDLETIME
 * Type: boolean
 * Default: TRUE

As per UnderNet CFV-165, this removes idle time in replies to /WHOIS.

HIS_WHO_SERVERNAME
 * Type: boolean
 * Default: TRUE

As per UnderNet CFV-165, this removes server names in replies to /WHO.

HIS_WHO_HOPCOUNT
 * Type: boolean
 * Default: TRUE

As per UnderNet CFV-165, this replaces hopcount to a static 3 in
replies to /WHO.

HIS_MODEWHO
 * Type: boolean
 * Default: TRUE

As per UnderNet CFV-165, this doesn't show which server performed a channel
mode change.

HIS_BANWHO
 * Type: boolean
 * Default: TRUE

As per UnderNet CFV-165, this doesn't show which server set a ban.

HIS_KILLWHO
 * Type: boolean
 * Default: TRUE

As per UnderNet CFV-165, this doesn't show which server or oper performed a
kill.

HIS_REWRITE
 * Type: boolean
 * Default: TRUE

As per UnderNet CFV-165, this remaps remote numerics to come from the local
server.

HIS_REMOTE
 * Type: integer
 * Default: 1

As per UnderNet CFV-165, this disallows remote queries. (*sob!*)

HIS_NETSPLIT
 * Type: boolean
 * Default: TRUE

As per UnderNet CFV-165, this removes server names in net break sign-offs.

HIS_WHOIS_LOCALCHAN
 * Type: boolean
 * Default: TRUE

As per UnderNet CFV-165, this removes local channels in replies to /WHOIS.

HIS_SERVERNAME
 * Type: string
 * Default: "*.undernet.org"

As per UnderNet CFV-165, this is the "name" of the server shown to users on a
/WHOIS of another user.

HIS_SERVERINFO
 * Type: string
 * Default: "The Undernet Underworld"

As per UnderNet CFV-165, this is the "info" of the server shown to users on a
/WHOIS of another user.

HIS_URLSERVERS
 * Type: string
 * Default: "http://www.undernet.org/servers.php"

As per UnderNet CFV-165, this is the URL shown to users when they do a /MAP or
/LINKS.

NETWORK
 * Type: string
 * Default: "UnderNet"

This defines the network name as reported in the 005 "supported features"
numeric, and as used by the "Failed to deliver" message.

URL_CLIENTS
 * Type: string
 * Default: "ftp://ftp.undernet.org/pub/irc/clients"

This defines a URL that users may visit to find compatible IRC clients.

NICKLEN
 * Type: integer
 * Default: 12

This is the allowed length of the nickname length.  It may not be
larger than the NICKLEN #define, and should usually be the same
length.  The real purpose of this feature is to permit easy increases
in nickname length for a network.

IRCD_RES_RETRIES
 * Type: integer
 * Default: 2

This is the number of attempts the irc daemon's resolver will have at
trying to solicit a response from the DNS server.

IRCD_RES_TIMEOUT
 * Type: integer
 * Default: 4

When a DNS query is sent, the irc daemon's resolver will wait this many
seconds for a reply.  After this timeout has expired, it will retry again,
for as many retries as IRCD_RES_RETRIES allows.  This can be cut short by
AUTH_TIMEOUT expiring.
NOTE: Has no effect when using the adns resolver.

AUTH_TIMEOUT
 * Type: integer
 * Default: 9

This is the maximum number of seconds to wait for the ident lookup and
the DNS query to succeed.  On older (pre 2.10.11.06) servers this was
hard coded to 60 seconds.

IPCHECK_CLONE_LIMIT
 * Type: integer
 * Default: 4

The number of times you are allowed to connect within IPCHECK_CLONE_PERIOD
seconds before you are considered abusing the server and throttled.

IPCHECK_CLONE_PERIOD
 * Type: integer
 * Default: 40

The number of seconds you are allowed to connect IPCHECK_CLONE_LIMIT times
within before you are considered abusing the server and throttled.
For instance if you set IPCHECK_CLONE_LIMIT to 1, and IPCHECK_CLONE_PERIOD
to 10, then a user is only allowed to connect once in 10s, if they connect
again within 10s, then they are considered to be connecting too fast and
they are throttled.

IPCHECK_CLONE_DELAY
 * Type: integer
 * Default: 600

The number of seconds grace after restarting the server before the throttle
code kicks in.  Even if a user connects repetitively during this period,
they will never get throttled.  This is so after a restart users on a
multiuser box can all connect to a server simultaniously without being
considered an attack.

SOCKSENDBUF
 * Type: integer
 * Default: 61440

The send window size used for connections to other servers.

SOCKRECVBUF
 * Type: integer
 * Default: 61440

The receive window size used for connections to other servers.

ANNOUNCE_INVITES
 * Type: boolean
 * Default: FALSE

If set, send RPL_ISSUEDINVITE (345) to a channel's operators to
announce when someone is invited to the channel.

LOCAL_CHANNELS
 * Type: boolean
 * Default: TRUE

If set, allow users to create local channels.

TOPIC_BURST
 * Type: boolean
 * Default: FALSE

If set, send the current topic value and timestamp for channels during
burst.  This generally only makes sense for hubs to use, and it causes
a large increase in net.burst size.

CHANNELLEN
 * Type: integer
 * Default: 200

This is the allowed length of locally created channels.  It may not be
larger than the CHANNELLEN #define.  Like the NICKLEN feature, this is
intended to ease changes in channel name length across a network.

OPLEVELS
 * Type: boolean
 * Default: TRUE

This allows local users to set the +A and +U modes (admin and user
passwords, respectively) on channels where they are marked as channel
managers.  This feature must be disabled until all servers on the
network are able to interpret and handle these modes correctly.

ZANNELS
 * Type: boolean
 * Default: TRUE

This preserves empty channels with no admin password so that it is
impractical to become the channel manager by clearing out the channel.
It must be set to FALSE if there are both 2.10.11.x servers and
2.10.12.y servers on the network where y < 4.  It should be set to
TRUE whenever the OPLEVELS features is TRUE.