Review 40 CFR 261 (particularly 261.1 through 9) and share three items that you

Review 40 CFR 261 (particularly 261.1 through 9) and share three items that you learned, found surprising, or generally caught your interest…be sure to explain why these items were chosen. Can you tie any of this into current events or changes in U.S. applications?  
https://www.govinfo.gov/content/pkg/CFR-2012-title40-vol27/xml/CFR-2012-title40-vol27-part261.xml