title: Custom error message in message.properties
body: <p>I've got <strong>Form</strong> domain class and there is  <strong>typeOfTransaction</strong> property. This property is required (blank: false). I want to write custom error message for this property, if the user does not set the value, the message must be appeared. </p>
  
  <pre><code>com.example.domain.form.typeOfTransaction.blank = Type of transaction required
  </code></pre>
  
  <p>Above is the message, but I don't get it when I'm trying to save form with empty <strong>typeOfTransaction</strong> field. Instead of this message I've got default message</p>
  
  <pre><code>"Please select an item in the list."
  </code></pre>
  
  <p>p.s. I don't know where this default message is defined.</p>