In the Developer Documentation > Signaling Function Reference, the following signaling functions are not included. They are very useful in signal scripts!! Call( "GetLinkApproachControl", LinkNumber ) - state of checkbox "approach control", 0 or 1 Call( "GetLinkLimitedToYellow", LinkNumber ) - state of checkbox "limited aspect", 0 or 1 Call( "GetLinkFeatherChar", LinkNumber ) - Contents of "Name of Route" field, integer (ASCII code, 1st char only) Call( "GetLinkSpeedLimit", LinkNumber ) - Contents of "Speed of Route" field, integer Call ( "GetId" ) - Contents of the ID field, string Are there others? I was lucky to have found this while surfing forum posts. I am also unsure of the meanings, and the signal behaviors that may be implied by setting these signal options.