$100,000 for 5 years (though, again, my specific numeric suggestions were mostly an example placeholder, not the result of considered thinking about what exact values make the most economic sense).

It's also not clear to me that continued updates wouldn't reset the term.

So, if they wanted to maintain a copyright on the 2006 version of DF (v0.21.93.19a, released August 2006), they would need to pay $500 in 2011, and $5,000 in 2016, and $100k in 2021, for a total payment to the unitd sates treasury of $105,500.

However, even if they paid nothing the latest release (50.09, released June 28, 2023) would remain under copyright automatically and for free until June 28, 2028. So they _could_ choose to let the community have access to the oldest versions of DF under public domain, while retaining copyright on the most recent versions. Or they could choose to pay to keep even the initial versions locked up.

I'd also probably want to make sure that the legislative language ensured that you didn't have to pay the copyright registration on each patch release. So, if the DF team paid for the initial version to remain under copyright, _all_ the patch versions would retain that same copyright status without needing to be individually paid for. That seems like an implementation detail for the legislation that would be important to get right, but I didn't feel it was important to specify in the proposal.