/serversigns silent

This command allows a server owner to define whether or not the ServerSigns plugin can display it’s own messages to players such as error messages when they interact with specific individual signs. Use the command /serversigns silent true to enable this behavior, or /serversigns silent false to return a ServerSigns-controlled sign to verbose mode.

To clarify, this only affects messages that are generated by the operation of ServerSigns itself. It does not mute any action commands that are added to the sign that sends text to players such as the /say or /tell commands.