By default, IRC4Fun only allows 3 simultaneous connections from an IPv4 or IPv6 address - but if you manage or are responsible for a bouncer, hosting, shell, TheLounge or znc service...
If you are trying to connect to IRC4Fun, but are being told you are either A-Lined, K-Lined, G-Lined, GA-Lined, or Z-Lined; this guide explains why and how to go about appealing the ban.