title: Validating forms with common rules using jQuery
body: <p>I've got multiple forms, all of them share common fields (for example <code>email</code>), and each one has unique fields (for example, <code>uniqueFieldA</code> on Form A, and <code>uniqueFieldB</code> on Form B ).</p>
  
  <p>What I want to do: Write a set of validation rules (using the <a href="http://docs.jquery.com/Plugins/Validation/" rel="nofollow">jQuery Validation Plugin</a>) for the common fields <em>once</em>, and "include" those rules in multiple places (each form), then add in the rules unique to that particular form.</p>
  
  <p>Something like this:</p>
  
  <p>Simplified HTML:</p>
  
  <pre><code>&lt;form id="formA"&gt;
    &lt;input name="email" /&gt;
    &lt;input name="uniqueFieldA" /&gt;
  &lt;/form&gt;
  
  &lt;form id="formB"&gt;
    &lt;input name="email" /&gt;
    &lt;input name="uniqueFieldB" /&gt;
  &lt;/form&gt;
  </code></pre>
  
  <p>JS:</p>
  
  <pre><code>// Define rules common to all forms
  var commonRules = { 
    email: {
      required: true,
      email: true
    },
  }
  
  // Define rules for form A
  $("#formA").validate({
     rules: {
       commonRules, //"include" common rules
       uniqueFieldA: "required" //rule unique to this form
     }
  })
  
  // Define rules for form B
  $("#formB").validate({
     rules: {
       commonRules, //"include" common rules
       uniqueFieldB: "required" //rule unique to this form
     }
  })
  </code></pre>
  
  <p>What will achieve this (assuming the full, correct HTML was used)?</p>