Not by a single federal mandate specific to yard ramps, but they’re standard on any ramp used where people or wheeled equipment work near the open edge.
Side rails, curbs, and safety chains solve a different problem than dock anchoring: they keep pedestrians, forklift wheels, and cargo from going off the side of the deck, rather than keeping the ramp itself from shifting against the dock.
General OSHA walking-working-surface and fall-protection standards apply to any elevated work surface your team uses, and most reputable manufacturers include side rails standard rather than as an add-on.
If your ramp sees foot traffic nearby or gets used in wet or icy conditions, treat curbs and chains as required equipment for your operation, whatever the baseline regulation says.
Full breakdown: Are Safety Curbs Required?



