Server notice channels in ircd v2.9

In IRC server version 2.8 there was usermode +s, which controlled showing server notices to users. In server version 2.9 that usermode has been removed, and as replacement there are multiple notice channels. These channels start with & prefix, and normal chat isn't possible on them.

The new channels are:

Error messages concerning server and network.
Informative and administrative notices from server.
Kill messages for users, collisions.
Channel mode desynchronation warnings.
IRC server protocol errors between servers, misrouted replies.
Introduction of new servers and splits of existing ones.
Server internal hash lookup table statistics.
Server local configuration warnings.
Introduction of new services and quits of existing ones.