title: Why do most fields (class members) in Android tutorial start with `m`?
body: <p>I know about camel case rules, but I'm confused with this m rule. What does it stand for? I'm a PHP developer. "We" use first letters of variables as indication of type, like 'b' for boolean, 'i' for integer and so on.</p>
  
  <p>Is 'm' a Java thing? Does it stand for mobile? mixed?</p>