Expert Sleepers Silent Way v2.4.3 - Manual (Page 69)

Reset By Note
The ‘Reset’ button, when enabled, causes the LFO to retrigger (i.e. start
from the beginning of its waveform) whenever the plug-in receives a
MIDI note-on message. This is useful when you effectively want to use the
LFO as a complex and looping envelope generator, instead of a traditional free-running
LFO.
The ‘Phase’ button sets the point in the waveform that the LFO jumps to when reset by a
MIDI note.