title: font-feature-settings: What is the correct syntax?
body: <p>I purchased a webfont that supports some open type features and of course I want to use them.<br>
  Unfortunately, I wasn't able to find a source online that explains the best way to use the syntax - it seems to me that <code>font-feature-settings</code> are another example of prefix hell.  </p>
  
  <p>At the moment I have it written like that but I am not sure if it covers really all browsers that support those features.</p>
  
  <pre><code>.element {
      -webkit-font-feature-settings: "kern" 1, "liga" 1, "case" 1;
         -moz-font-feature-settings: "kern=1", "liga=1", "case=1";
         -moz-font-feature-settings: "kern" on, "liga" on, "case" on;
          -ms-font-feature-settings: "kern" 1, "liga" 1, "case";
           -o-font-feature-settings: "kern", "liga", "case";
              font-feature-settings: "kern", "liga", "case";
  }
  </code></pre>
  
  <p>More specifically, the <code>-moz</code> syntax seems strange. Some sources claim that this is the syntax to be used:  </p>
  
  <pre><code>-moz-font-feature-settings: "liga=1";  /* Firefox 14 and before */
  -moz-font-feature-settings: "liga" on; /* Firefox 15 */
  </code></pre>
  
  <p>Others do it simply like this:  </p>
  
  <pre><code>-moz-font-feature-settings: "cswh=1";
  -moz-font-feature-settings: "cswh";
  </code></pre>
  
  <p>The same goes for <code>-webkit</code>; some write it like that:  </p>
  
  <pre><code>-webkit-font-feature-settings: "liga" on, "dlig" on;
  </code></pre>
  
  <p>While others do it like this:  </p>
  
  <pre><code>-webkit-font-feature-settings: "liga", "dlig";
  </code></pre>
  
  <p>Or like this:  </p>
  
  <pre><code>-webkit-font-feature-settings: "liga" 1, "dlig" 1;  
  </code></pre>
  
  <p>And on top, there is also <code>text-rendering: optimizelegibility;</code> which seems to be the same as <code>"kern"</code> and <code>"liga"</code>, at least in webkit browsers.  </p>
  
  <p>So, what is the correct, bulletproof way to use Open Type font features on the web in 2013?</p>