title: Where did these .htaccess rules come from, and what exactly do they do?
body: <p>Late last year my web host added the following rules to my .htaccess file for my domain.</p>
  
  <pre><code>#RewriteCond %{REQUEST_URI} !^/\.well-known/acme-challenge/[0-9a-zA-Z_-]+$
  #RewriteCond %{REQUEST_URI} !^/\.well-known/cpanel-dcv/[0-9a-zA-Z_-]+$
  #RewriteCond %{REQUEST_URI} !^/\.well-known/pki-validation/(?:\ Ballot169)?
  #RewriteCond %{REQUEST_URI} !^/\.well-known/pki-validation/[A-F0-9]{32}\.txt(?:\ Comodo\ DCV)?$
  </code></pre>
  
  <p>I tried searching the internet for this Ballot169 term, and saw that other people have labeled this particular set of rules as some sort of DDOS protection. What attack is this preventing? What is this Ballot169 folder? Is it part of the normal functioning of cPanel SSL configuration? </p>
  
  <p>I also use Let's Encrypt, but couldn't find any indication that it was related.</p>