title: What does it mean by 'state-dependent encodings'? What does it mean by 'same byte values'? What does mean by 'initial and non-initial shift states'?
body: <p>I'm using <strong>Windows 10 Home Single Language Edition</strong> which is a <strong>64-bit Operating System</strong> on my machine.</p>
  
  <p>I've installed the most latest version of <strong>XAMPP</strong>  which has installed <strong>PHP 7.2.6</strong> on my machine.</p>
  
  <p>I come across the following sentence from the paragraph in <a href="https://secure.php.net/manual/en/language.types.string.php#language.types.string.details" rel="nofollow noreferrer">PHP Manual</a> </p>
  
  <p>I understood most part of the paragraph from <a href="https://secure.php.net/manual/en/language.types.string.php#language.types.string.details" rel="nofollow noreferrer">PHP Manual</a>. But, I didn't understand the last sentence from the same paragraph which I've mentioned below.</p>
  
  <blockquote>
    <p>Note, however, that state-dependent encodings where the same byte
    values can be used in initial and non-initial shift states may be
    problematic.</p>
  </blockquote>
  
  <p>I've following questions in context of the paragraph titled <a href="https://secure.php.net/manual/en/language.types.string.php#language.types.string.details" rel="nofollow noreferrer">Details of the String Type</a></p>
  
  <ol>
  <li>What does it mean by 'state-dependent encodings' in this context?</li>
  <li>What does it mean by 'initial and non-initial shift states' in this context?</li>
  <li>What does mean by 'same byte values' that can be used in above mentioned 'initial and non-initial' shift states in this context?.
  4.How does the same byte values can be used in 'initial and non-initial shift states' and how it can be problematic?</li>
  </ol>