title: Mongoose schema optional fields
body: <p>I have a user schema with mongoose in nodejs like this</p>
  
  <pre><code>userschema = mongoose.Schema({
      org: String,
      username: String,
      fullname: String,
      password: String,
      email: String
  });
  </code></pre>
  
  <p>Except sometimes I need to add some more fields.</p>
  
  <p><strong>The main question is: Can I have optional fields in a monogoose schema?</strong></p>