Rules online

[jchamp]

Originally Posted by Robert Goodman

But pretty ineffective against material that's already in the public domain.

From page 1 of the *.pdf file in question:

© 2011, This rules book has been copyrighted by the National Federation of State High School Associations with the United States Copyright Office. No one may republish any material contained herein without the prior written consent of the NFHS.
Republication of all or any portion of this rules book on the Internet is expressly prohibited.

I think that's pretty clear. It's possible they got permission, and no one outside of that particular discussion would need to know.
Otherwise, it's still a copyrighted work. If the NFHS sends a DMCA takedown notice to the web-hosting company or ISP, and that company doesn't at least pass the word on, then there is serious litigation possibility at stake. At the end of the day, it's best to not screw with it unless you've got the documentation that proves you were given permission.
There is certainly a legitimate point that the rules may be public domain, but there's lots in there besides rules.