I think parent means that even if you "sign a contract assigning all IP to their employer", you can still write OSS code in your free time, since there is no wa

I think parent means that even if you "sign a contract assigning all IP to their employer", you can still write OSS code in your free time, since there is no way your employer will find out, and even if they do, they've no way to prove you wrote it, except if you "sign it", which no one does.