CHANNEL MODE j

Usage: MODE <room> +|-j

j - Java Clients Only

This command allows you to have only java clients and sellected legacy IRC clients enter the specified channel. For this mode to take effect you must set a key. For IRC clients to enter the channel they must supply the key, or be invited into the channel.

Privilege: Channel Operator

See also: CMODE k

Examples:
/mode #webchat +j