title: When to use "?android" or "@android"?
body: <p>I am a newbie and trying to understand the following XML code:</p>
  
  <p></p>
  
  <p>Looking at the documentation at developer.android.com, it says "starStyle" is a constant in R.attr and </p>
  
  <hr>
  
  <p>public static final int starStyle
  Since: API Level 1</p>
  
  <p>Default Star style.</p>
  
  <h2>Must be a reference to another resource, in the form "@[+][package:]type:name" or to a theme attribute in the form "?[package:][type:]name".</h2>
  
  <p>It seems to say that there are 2 syntax I can declare.  1) "@[+][package:]type:name" 2) "?[package:][type:]name".</p>
  
  <p>If there are 2 syntax, what is the correct one for "@[+][package:]type:name" ?</p>
  
  <p>I tried ""@android:attr/starStyle" but I didn't get a "star" checkbox even though the application compiled ok.</p>