Since derived properties are not set by user input, there are no input, but only output fields for them in a user interface. This is illustrated in the following example of an HTML form:

<form id="Person">
 <label>First name: <input name="firstName" type="text"/></label>
 <label>Last name: <input name="lastName" type="text"/></label>
 <label>Initials: <output name="initials"/></label>
 <label>Date of birth: 
  <input name="dateOfBirth" type="date"/></label>
 <label>Age: <output name="age"/></label>
</form>