In the same way a lot of the other rules on that list are. How are they going to know you are familiar with the code you are committing? How are they going to know it is tested?

Sometimes rules are established to set up a common community base line. You are trusted to follow them in good faith. If over time, through code review, questioning or testing, it shows you aren't following the rules then you can't claim you didn't know it wasn't okay.

This stance is CYA. There's no way to enforce it but by stating explicitly like this, they save themselves possible legal pain.

The headline of this HN post is misleading, it isn't really a "ban" as such and doesn't have to be "enforceable." These are guidelines whose target audience is good-faith developers who want to make positive contributions to NetBSD.

The comments saying "heh, those stoopid NetBSD maintainers would never know if I slipped a bit of AI into their codebase" are missing the point. The point of the guideline is to say that people who use Copilot/etc for NetBSD development are dumb assholes, so don't be a dumb asshole.

Seems impossible to me, although it seems more of some sort of protection in case of legal problems should someone add AI-generated code that turns out to contain copyrighted code by someone else. They must show they're doing something against that, even if that something turns out to be probably useless.

its not about enforceability its simply about covering their ass

yeah doesn't make any sense lol

if you remove comments and shift it to your own style then it's not going to be distinguishable except for sufficiently complex code where your own codebase's unique idioms may show through and the AI doesn't use them