drupal_theme_hook.php

<?php 
/**
* Implementation of hook_theme().
*/
function custom_theme() {
  return array(
    'find_a_profile_form' => array(
    'arguments' => array('roles' => array(), 'subjects' => array(), 'regions' => array()),
    'template' => 'find-a-profile-form',
    ),
    'theme_username' => array(
      'arguments' => 'object'
        
      )
    )
  );
}


function custom_theme_username($object) {

  if ($object->uid && $object->name) {
    // Shorten the name when it is too long or it will break many tables.
    if (drupal_strlen($object->name) > 20) {
      $name = drupal_substr($object->name, 0, 15) . '...';
    }
    else {
      $name = $object->name;
    }

    if (user_access('access user profiles')) {
      $output = l($name, 'user/' . $object->uid, array('attributes' => array('title' => t('View user profile.'))));
    }
    else {
      $output = check_plain($name);
    }
  }
  else if ($object->name) {
    // Sometimes modules display content composed by people who are
    // not registered members of the site (e.g. mailing list or news
    // aggregator modules). This clause enables modules to display
    // the true author of the content.
    if (!empty($object->homepage)) {
      $output = l($object->name, $object->homepage, array('attributes' => array('rel' => 'nofollow')));
    }
    else {
      $output = check_plain($object->name);
    }

    $output .= ' (' . t('not verified') . ')';
  }
  else {
    $output = check_plain(variable_get('anonymous', t('Anonymous')));
  }

  return $output;
}

 ?>