Soft Rev Limit
Set this parameter to the RPM you want the engine limited. The rev limiter cuts the ignition in a specific sequence to prevent spark plugs from fowling when rev limiting. It can be set a little lower than the absolute maximum RPM and the hard rev limiter can be set to the absolute maximum RPM. This will give double protection from over revving an engine.
To disable the Soft Rev Limiter set it to 0 RPM.