Many Stomps have time based controls such as LFO rate or Delay time. Some of these Stomps can sync to the host BPM using a musical note duration to represent the rate or time of the parameter. Manual Rate or Time is set in milliseconds or seconds. Sync Rate is expressed using note durations from 2 whole notes to 1/32nd note triplets as shown in this diagram:
Waves Guitar Tool Rack User Guide.