Which Kind of Line Coding is This?

I've run across a particular line coding scheme in a couple of places, and I'm wondering what it's called. The example below comes from the Concealed Display protocol for the Valentine One RADAR detector:

View attachment 68578

Google reveals plenty of information for the more common line coding schemes (RZ, NRZ, Manchester, etc.) but none of those seems to match this exactly. Manchester seems to come the closest, but in Manchester coding the transition always occurs in the exact middle of the bit time, whereas in this scheme the transitions occur either 1/3 or 2/3 of the way through.

Since this scheme is not unique to the Valentine One, I assume it must be pretty standard, but what is it called?

Thanks for your help!

so it's a proprietary, modified version of Manchester.

It's pulse width coded, each bit is at a 503uS total period (fixed bitrate);
a 0 bit has a high period of 503uS /3
a 1 bit has a high period of 503uS /2