It is zero-sensitivity (for area) at motion detector.
Sometime it is required to have motion detection with some alarm assigned and continuous recording (often snapshots) into another destination (for example to HTTP or FTP server).
In this case motion alarm are configuring as usual.
And, an additional “continue recording” destination must be configured as another motion detector’s area, but with zero (“0”) sensitivity. Thus, assigned destinations (handlers) will continuously work with necessary intervals.