[sfink]

> feel free to copy and claim as your own.

That's a nice sentiment, but I'd encourage you to add a license or something. The basic "something" would be adding a canonical URL into the spreadsheet itself somewhere, along with a notification that users can do what they want other than removing that URL. (And the URL would be described as "the original source" or something, not a claim that the particular version/incarnation someone is looking at is the same as what is at that URL.)

The risk is that someone will accidentally introduce errors or unsupportable claims, and people with the modified spreadsheet won't know that it's not The spreadsheet and so will discount its accuracy or trustability. (If people are trying to deceive others into thinking it's the original, they'll remove the notice, but that's a different problem.) It would be a shame for people to lose faith in your work because of crap that other people do that you have no say in.