What is this ?
Types of sync signals
Composite sync, where the horizontal and vertical signals are mixed together on a separate wire (S).
Separate sync, where the horizontal and vertical are each on their own wire (HV).
RGsB / SoG
Sync on green, where a composite sync signal is overlaid on the wire used to transport the green signal.
Sync on red or sync on blue, where a composite sync signal is overlaid on either the red or blue wire.
Sync on luminance, similar to sync on green, but combines sync with the luminance signal (Y).