Specifically, our solution leverages the 10-digit code the FAA provides to those who register their drone, which must be legibly printed somewhere on the frame of the device. The challenge is that a drone’s ID cannot be read unless somebody is in close proximity to the device, making it almost impossible to identify drones that are in flight.

Therefore, we looked at using the anti-collision lights that several drones offer to improve their visibility during nighttime operations. Our patent-pending idea is to use the lights to broadcast a drone’s 10-digit code in an ASCII-encoded binary signal at a baud rate — one that could be synced for consistency across the system to ensure universal compatibility.

Source: Why a Car Company Is Looking to the Skies: A Glimpse into Ford’s Drone Research

This is from a Ford blog post in March of 2018. The Ford proposal is even simpler than Intel’s Open Drone ID system.

We will be taking a look at proposals from Amazon, Google and perhaps others. Some proposals are workable, while others have high costs and complexity and would likely end much of the model aircraft hobby, especially quadcopters.