title: Custom Unobtrusive Validation Method Not Firing as Per Documentation
body: <p>I've been attempting to implement a ASP.NET MVC custom validation method. Tutorials I've used such as <a href="https://www.codeproject.com/Articles/275056/Custom-Client-Side-Validation-in-ASP-NET-MVC" rel="nofollow noreferrer">codeproject</a> explain that you add <code>data-val-customname</code> to the element. Then <code>jQuery.validate.unobtrusive.js</code> then uses the third segment of the attribute</p>
  
  <p><code>data-val-&lt;customname&gt;</code> </p>
  
  <p>as the name of the rule, as shown below.</p>
  
  <pre><code>$.validator.addMethod('customname', function(value, element, param) {
      //... return true or false
  });
  </code></pre>
  
  <p>However I just can't get the customname method to fire. By playing around I have been able to get the below code to work, but according to all the sources I've read Unobtrusive validation should not work like this.</p>
  
  <pre><code>$.validator.addMethod('data-val-customname', function(value, element, param) {
      //... return true or false
  });
  </code></pre>
  
  <p>I've posted an example of both methods 
  <a href="https://jsfiddle.net/johnhornsby/2hk3kqzk/" rel="nofollow noreferrer">jsfiddle example</a></p>
  
  <p>Any help would be much appreciated </p>
  
  <p>I've updated my question hopefully to make clearer.</p>