I understand how to place an icon in a text field to indicate to the user that it is required and in HTML5 form get the tip indicating that the field should be filled out.

is there any similar mechanism for radio buttons and check boxes?

Below is a simple group of radio buttons that I am using.

```html
  <!DOCTYPE html>

  <polymer-element name='marital-status-form'>
    <template>
    <style">

      #col1 { order:1; }
      #col2 { order:2; align-self:flex-start; }
      #hr { order:3; }

    </style>
      <form id='form'
            name='form'
            on-change='{{updateModel}}'>

        <section 
          <label for='marriedRdo' id='marriedLbl' >Married</label>
          <label for='divorcedRdo' id='divorcedLbl' >Divorced</label>
          <label for='singleRdo' id='singleLbl' >Single</label>
          <label for='visitingRdo' id='visitingLbl' >Visiting</label>

        </section>

        <section >
          <input id='marriedRdo'
                 name='status'
                 type="radio"
                 value='Married'
                 on-click='{{submit}}'>
          <input id=divorcedRdo name='status' type='radio' value='Divorced'>
          <input id='singleRdo' name='status' type="radio" value='Single' >
          <input id=visitingRdo name='status' type='radio' value='Visiting'>
        </section>

        <hr id='hr'>
        <delete-dispatch-form id='delete-dispatch-form'></delete-dispatch-form>

        <button id='submit-btn'
          type='submit'></button>

        </form>
      </template>

     <script type="application/dart">

      import 'package:polymer/polymer.dart' show CustomTag, observable, PolymerElement;

      import 'dart:html' show Event, Node, InputElement;

      @CustomTag( 'marital-status-form')
      class MaritalStatusForm extends RooleElement
      {
        @observable String choice= '';

        MaritalStatusForm.created() : super.created();

        void updateModel(Event e, var detail, Node target)
        {
          //maritalStatus.status = (e.target as InputElement).value;

          //print( encode( maritalStatus ) );

        }

        void submit ( Event e, var detail, Node target )
        {
          $['form'].onSubmit.listen( ( e )
              {
                e.preventDefault();
              } );
        }

      }

    </script>
  </polymer-element>

```