The docking spacecraft must follow a NASA standard[1] to avoid building up electrostatic charge.
From the Commercial Crew requirements document[2]:
3.9.3.13 Integrated Space Vehicle Electrostatic Charge Control
3.9.3.13.1 LEO Charging Design Standard
The spacecraft shall meet the intent of the requirements contained in NASA-STD-4005, Low
Earth Orbit Spacecraft Charging Design Standard. [R.CTS.285]
How the contractors achieve that might be proprietary. It looks like (at one time) SpaceX used electrically conductive paint[3] as part of their mitigations.
You missed this one: "International Docking System Standard
(IDSS)" [0] which I actually read that before answering hence my "required by the docking standard".
You will see that it says: "IDSS compliant mechanisms protect against electrostatic discharge through the soft capture system" which is to say not much.
That’s still more than the previous standard for which the paragraph on ESD just says "RESERVED".
From the Commercial Crew requirements document[2]:
How the contractors achieve that might be proprietary. It looks like (at one time) SpaceX used electrically conductive paint[3] as part of their mitigations.[1] https://standards.nasa.gov/standard/NASA/NASA-STD-4005
[2] https://ntrs.nasa.gov/api/citations/20150010757/downloads/20...
[3] https://phys.org/news/2013-03-white-coating-spacex-dragon-tr...