Question: Every example of "depends" I can find on the web uses the "required" rule. Clearly this is not sufficient. How do I use the "depends" clause with, for example, a "regex" rule?

I have two radio buttons, if one is selected, I regex-validate a textbox. If the other is selected, I don't care what is in the textbox.

Answer: 
The [2nd example in the documentation uses email](http://jqueryvalidation.org/validate/#rules):

```
$(".selector").validate({
  rules: {
    contact: {
      required: true,
      email: {
        depends: function(element) {
          return $("#contactform_email:checked")
        }
      }
    }
  }
});

```

In summary, that rule is saying "contact is required and it must be an email address if `#contactform_email` checkbox is checked".

So if you wanted to do that with a regex (or any parameter-requiring rule method), it looks like this:

```
        minlength: {
            param:6,
            depends: function (element) {
                return $('#len').is(':checked');
            }
        }

```

Which says "The min length is 6 but only when the `#len` checkbox is checked".

See it in action here: <http://jsfiddle.net/ryleyb/8Nsm3/>
You can also directly use function() in rules as below:

```
rules: {
    "field_name": {
        required: function () {
            return $('#len').is(':checked');
        },
    },
}
......
......

```