title: Regex matching uppercase characters with lowercase search
body: <p>I'm using notepad++ and I'm finding that when I use regex to search for strings where I specifically want to find lowercase letters ("[a-z]") it will sometimes return uppercase letters.</p>
  
  <p>I originally was searching using the string:</p>
  
  <pre><code>^[A-Z][a-z].+?$
  </code></pre>
  
  <p>With the purpose of deleting any line in my file that began with an uppercase character, followed by a lowercase, followed by anything until the end of the line. However, this returned lines like, "CLONE" and "DISEASE" which were only capital letters. Out of curiosity, I tried:</p>
  
  <pre><code>^[a-z].+?$
  </code></pre>
  
  <p>And it still returned those lines in all-caps. Finally, I tried:</p>
  
  <pre><code>^[\u0061-\u007A].+?$
  </code></pre>
  
  <p>And it <em>still</em> returned lines of all-caps text. Is there something outside of my brackets that's causing this to happen?</p>