diff --git a/classes/board.php b/classes/board.php
index 5c35617..56098a4 100644
--- a/classes/board.php
+++ b/classes/board.php
@@ -25,17 +25,35 @@
 
 defined('MOODLE_INTERNAL') || die;
 
-define('ACCEPTED_FILE_EXTENSIONS', 'jpg,jpeg,png,bmp,gif');
-define('ACCEPTED_FILE_MIN_SIZE', 100); // 100 bites
-define('ACCEPTED_FILE_MAX_SIZE', 1024 * 1024 * 10); // 10Mb
-define('RATINGDISABLED', 0);
-define('RATINGBYSTUDENTS', 1);
-define('RATINGBYTEACHERS', 2);
-define('RATINGBYALL', 3);
-define('SORTBYDATE', 1);
-define('SORTBYRATING', 2);
-
 class board {
+
+    /** @var string String of accepted file types. */
+    const ACCEPTED_FILE_EXTENSIONS = 'jpg,jpeg,png,bmp,gif';
+
+    /** @var int Minumum file size of 100 bytes. */
+    const ACCEPTED_FILE_MIN_SIZE = 100;
+
+    /** @var int Maximum file size of 10Mb. */
+    const ACCEPTED_FILE_MAX_SIZE = 1024 * 1024 * 10;
+
+    /** @var int Value for disabling rating. */
+    const RATINGDISABLED = 0;
+
+    /** @var int Value for allowing students to rate posts. */
+    const RATINGBYSTUDENTS = 1;
+
+    /** @var int Value for allowing teachers to rate posts */
+    const RATINGBYTEACHERS = 2;
+
+    /** @var int Value for allowing all roles to rate posts */
+    const RATINGBYALL = 3;
+
+    /** @var int Value for sorting all posts by date */
+    const SORTBYDATE = 1;
+
+    /** @var int Value for sorting all posts by rating */
+    const SORTBYRATING = 2;
+
     /**
      * Retrieves the course module for the board
      *
@@ -542,15 +560,15 @@ public static function store_note_file($noteid, $attachment) {
      */
     public static function valid_for_upload($attachment) {
         $fileextension = strtolower(array_pop(explode('.', basename($attachment['filename']))));
-        if (!in_array($fileextension, explode(',', ACCEPTED_FILE_EXTENSIONS))) {
+        if (!in_array($fileextension, explode(',', self::ACCEPTED_FILE_EXTENSIONS))) {
             return false;
         }
         $filelength = strlen($attachment['filecontents']);
 
-        if ($filelength < ACCEPTED_FILE_MIN_SIZE) {
+        if ($filelength < self::ACCEPTED_FILE_MIN_SIZE) {
             return false;
         }
-        if ($filelength > ACCEPTED_FILE_MAX_SIZE) {
+        if ($filelength > self::ACCEPTED_FILE_MAX_SIZE) {
             return false;
         }
 
@@ -915,11 +933,11 @@ public static function board_can_rate_note($noteid) {
 
         $iseditor = has_capability('mod/board:manageboard', $context);
 
-        if ($board->addrating == RATINGBYSTUDENTS && $iseditor) {
+        if ($board->addrating == self::RATINGBYSTUDENTS && $iseditor) {
             return false;
         }
 
-        if ($board->addrating == RATINGBYTEACHERS && !$iseditor) {
+        if ($board->addrating == self::RATINGBYTEACHERS && !$iseditor) {
             return false;
         }
 
diff --git a/mod_form.php b/mod_form.php
index b07ba06..f55809e 100755
--- a/mod_form.php
+++ b/mod_form.php
@@ -25,6 +25,8 @@
 
 require_once($CFG->dirroot.'/course/moodleform_mod.php');
 
+use mod_board\board;
+
 class mod_board_mod_form extends moodleform_mod {
     public function definition() {
         global $CFG, $DB;
@@ -60,10 +62,10 @@ public function definition() {
 
         $mform->addElement('select', 'addrating', get_string('addrating', 'mod_board'),
            array(
-                RATINGDISABLED => get_string('addrating_none', 'mod_board'),
-                RATINGBYSTUDENTS => get_string('addrating_students', 'mod_board'),
-                RATINGBYTEACHERS => get_string('addrating_teachers', 'mod_board'),
-                RATINGBYALL => get_string('addrating_all', 'mod_board')
+                board::RATINGDISABLED => get_string('addrating_none', 'mod_board'),
+                board::RATINGBYSTUDENTS => get_string('addrating_students', 'mod_board'),
+                board::RATINGBYTEACHERS => get_string('addrating_teachers', 'mod_board'),
+                board::RATINGBYALL => get_string('addrating_all', 'mod_board')
             )
         );
         $mform->setType('addrating', PARAM_INT);
@@ -73,8 +75,8 @@ public function definition() {
 
         $mform->addElement('select', 'sortby', get_string('sortby', 'mod_board'),
            array(
-                SORTBYDATE => get_string('sortbydate', 'mod_board'),
-                SORTBYRATING => get_string('sortbyrating', 'mod_board')
+                board::SORTBYDATE => get_string('sortbydate', 'mod_board'),
+                board::SORTBYRATING => get_string('sortbyrating', 'mod_board')
             )
         );
         $mform->setType('sortby', PARAM_INT);
diff --git a/view.php b/view.php
index afeba4b..a1ee019 100755
--- a/view.php
+++ b/view.php
@@ -61,9 +61,9 @@
     'post_max_length' => $config->post_max_length,
     'history_refresh' => $config->history_refresh,
     'file' => array(
-        'extensions' => explode(',', ACCEPTED_FILE_EXTENSIONS),
-        'size_min' => ACCEPTED_FILE_MIN_SIZE,
-        'size_max' => ACCEPTED_FILE_MAX_SIZE
+        'extensions' => explode(',', board::ACCEPTED_FILE_EXTENSIONS),
+        'size_min' => board::ACCEPTED_FILE_MIN_SIZE,
+        'size_max' => board::ACCEPTED_FILE_MAX_SIZE
     ),
     'ratingenabled' => board::board_rating_enabled($board->id),
     'hideheaders' => board::board_hide_headers($board->id),