Help for USERINFO:

The USERINFO command allows the definition of info lines
to be shown to the channel when a user joins.

When only the channel argument is given, a listing of
users with info lines will be displayed.

Syntax: USERINFO <#channel>

Otherwise, an info line is modified or deleted.

Syntax: USERINFO <#channel> <nickname> [newinfo]

The given nickname must be on the channel access list
and you must have permission to modify the entry (+f
plus the entry's flags).

Examples:
    /msg &nick& USERINFO #foo
    /msg &nick& USERINFO #foo foouser
    /msg &nick& USERINFO #foo foouser An info line.
