Ok. Total off-topic time.
So, zeroed the four-wire probes. They were 0.0012 ohms. Set to slow with 10 moving average samples. Using 100 range with a 100.000 .005% resistor. Last calibration 15 years (!)
Ok, spec after 1 year (max on datasheet) is 100+40, which is ppm reading plus range. So, I think this is 100*0.01%+100*0.004% or +/- 0.014 ohms.
So, my reading is 99.981.
So, in spec? Maybe?