learn how to fucking google
https://www.investopedia.com/terms/t/tax_exempt_security.asp
"
What is 'Tax-Exempt Security'
A tax-exempt security is an investment in which the income produced is free from federal, state, and/or local taxes. Most tax-exempt securities come in the form of municipal bonds, which represent obligations of a state, territory or municipality. For some investors, U.S. Savings Bond interest may also be free from federal income taxes."
Plus not sure why you are still talking about this shit. I already proved everything that needed to proof in my previous post.