title: Java variables 'm' and 'p' prefixes
body: <p>What are the purposes and meanings of this syntax? I'm seeing lines like <code>private Object mSelectedOperationRow;</code> and <code>mMessageService = pMessageService;</code>. 
  More complete code below.</p>
  
  <pre><code>public class SearchResponseBean extends BaseBean implements Serializable,
      SearchResponse {
  
  @Autowired
  private SearchLifecycleService mSearchLifecycleService;
  
  @Autowired
  private ConfigurationServiceImpl mConfig;
  
  @Value("#{sessionBean}")
  private Session session;
  
  @Value("#{searchRequestBean}")
  private SearchRequest searchRequest;
  
  @Value("#{searchResponseFilterByBean}")
  private SearchResponseFilterBy searchResponseFilterBy;
  
  @Value("#{searchHistoryBean}")
  private HistoryBean&lt;SearchHistoryItem&gt; historyBean;
  
  @Autowired
  private SearchResponseDataModelFactory mSearchResponseDataModelFactory;
  
  private int mCount;
  private DataModel mDataModel;
  private SearchPerspective mSearchPerspective;
  private Operation mSelectedOperation;
  private Object mSelectedOperationRow;
  private List mSelectedList;
  private List&lt;String&gt; mAvailableOperations;
  private List mFilteredList;
  private boolean mRelatedDocSearch;
  
  private transient MessageService mMessageService;
  
  public SearchResponseBean() {
      mMessageService = new MessageServiceImpl();
  }
  
  public SearchResponseBean(MessageService pMessageService) {
      mMessageService = pMessageService;
  }
  
  protected void init() {
      String THIS_METHOD_NAME = "init";
      mFilteredList = null;
      mSelectedList = null;
      mSelectedOperationRow = null;
      mSelectedOperation = null;
      mCount = -1;
      mDataModel = null;
      mSearchPerspective = null;
      mAvailableOperations = null;
      mRelatedDocSearch = false;
      logger.debug(getClass(), THIS_METHOD_NAME,
              "Initialized with null/defaults. ");
  }
  </code></pre>