title: Single versus double quotation marks in HTML & CSS
body: <p>Could anyone clarify the difference between single and double quotation marks in HTML5 &amp; CSS.</p>
  
  <p>Here's Google's contradictory use of single quotes in HTML:</p>
  
  <pre><code>&lt;link href='https://fonts.googleapis.com/css?family=Roboto' rel='stylesheet' type='text/css'&gt;
  </code></pre>
  
  <p>And CSS:</p>
  
  <pre><code>font-family: 'Roboto', sans-serif;
  </code></pre>
  
  <p>While Bootstrap's documentation practices demonstrate the use of double quoted marks in HTML: </p>
  
  <pre><code>&lt;link rel="stylesheet" href="https://cdn.rawgit.com/twbs/bootstrap/v4-dev/dist/css/bootstrap.css"&gt;
  </code></pre>
  
  <p>And CSS:</p>
  
  <pre><code>font-family:"Helvetica Neue",Helvetica,Arial,sans-serif;
  </code></pre>
  
  <p>Which practice is the <strong>best</strong> and <strong>why</strong> ? </p>
  
  <p>EDIT:
  Is there any <em>valid reason</em> why Google Fonts decided to use single quotes ?</p>