diff --git a/phpBB/docs/CHANGELOG.html b/phpBB/docs/CHANGELOG.html
index b64a67acf4..2e258df248 100644
--- a/phpBB/docs/CHANGELOG.html
+++ b/phpBB/docs/CHANGELOG.html
@@ -96,6 +96,7 @@
 		<li>[Fix] Added VST - Venezuela Standard Time (Bug #30545).</li>
 		<li>[Fix] Close DB connections in file.php.</li>
 		<li>[Change] Set headers to allow browsers to better cache attachments (Mylek pointed this out)</li>
+		<li>[Change] Hide parameters if they equal the default (Bug #31185)</li>
 
 
 </ul>
diff --git a/phpBB/viewforum.php b/phpBB/viewforum.php
index 12a6d940d1..d9b0fd41ec 100644
--- a/phpBB/viewforum.php
+++ b/phpBB/viewforum.php
@@ -26,9 +26,13 @@ $forum_id	= request_var('f', 0);
 $mark_read	= request_var('mark', '');
 $start		= request_var('start', 0);
 
-$sort_days	= request_var('st', ((!empty($user->data['user_topic_show_days'])) ? $user->data['user_topic_show_days'] : 0));
-$sort_key	= request_var('sk', ((!empty($user->data['user_topic_sortby_type'])) ? $user->data['user_topic_sortby_type'] : 't'));
-$sort_dir	= request_var('sd', ((!empty($user->data['user_topic_sortby_dir'])) ? $user->data['user_topic_sortby_dir'] : 'd'));
+$default_sort_days	= (!empty($user->data['user_post_show_days'])) ? $user->data['user_post_show_days'] : 0;
+$default_sort_key	= (!empty($user->data['user_post_sortby_type'])) ? $user->data['user_post_sortby_type'] : 't';
+$default_sort_dir	= (!empty($user->data['user_post_sortby_dir'])) ? $user->data['user_post_sortby_dir'] : 'd';
+
+$sort_days	= request_var('st', $default_sort_days);
+$sort_key	= request_var('sk', $default_sort_key);
+$sort_dir	= request_var('sd', $default_sort_dir);
 
 // Check if the user has actually sent a forum ID with his/her request
 // If not give them a nice error page.
@@ -212,7 +216,7 @@ $sort_by_text = array('a' => $user->lang['AUTHOR'], 't' => $user->lang['POST_TIM
 $sort_by_sql = array('a' => 't.topic_first_poster_name', 't' => 't.topic_last_post_time', 'r' => 't.topic_replies', 's' => 't.topic_title', 'v' => 't.topic_views');
 
 $s_limit_days = $s_sort_key = $s_sort_dir = $u_sort_param = '';
-gen_sort_selects($limit_days, $sort_by_text, $sort_days, $sort_key, $sort_dir, $s_limit_days, $s_sort_key, $s_sort_dir, $u_sort_param);
+gen_sort_selects($limit_days, $sort_by_text, $sort_days, $sort_key, $sort_dir, $s_limit_days, $s_sort_key, $s_sort_dir, $u_sort_param, $default_sort_days, $default_sort_key, $default_sort_dir);
 
 // Limit topics to certain time frame, obtain correct topic count
 // global announcements must not be counted, normal announcements have to
@@ -302,7 +306,7 @@ $template->assign_vars(array(
 
 	'U_MCP'				=> ($auth->acl_get('m_', $forum_id)) ? append_sid("{$phpbb_root_path}mcp.$phpEx", "f=$forum_id&amp;i=main&amp;mode=forum_view", true, $user->session_id) : '',
 	'U_POST_NEW_TOPIC'	=> ($auth->acl_get('f_post', $forum_id) || $user->data['user_id'] == ANONYMOUS) ? append_sid("{$phpbb_root_path}posting.$phpEx", 'mode=post&amp;f=' . $forum_id) : '',
-	'U_VIEW_FORUM'		=> append_sid("{$phpbb_root_path}viewforum.$phpEx", "f=$forum_id&amp;$u_sort_param&amp;start=$start"),
+	'U_VIEW_FORUM'		=> append_sid("{$phpbb_root_path}viewforum.$phpEx", "f=$forum_id" . ((strlen($u_sort_param)) ? "&amp;$u_sort_param" : '') . "&amp;start=$start"),
 	'U_MARK_TOPICS'		=> ($user->data['is_registered'] || $config['load_anon_lastread']) ? append_sid("{$phpbb_root_path}viewforum.$phpEx", "f=$forum_id&amp;mark=topics") : '',
 ));
 
@@ -514,7 +518,7 @@ if ($s_display_active)
 }
 
 $template->assign_vars(array(
-	'PAGINATION'	=> generate_pagination(append_sid("{$phpbb_root_path}viewforum.$phpEx", "f=$forum_id&amp;$u_sort_param"), $topics_count, $config['topics_per_page'], $start),
+	'PAGINATION'	=> generate_pagination(append_sid("{$phpbb_root_path}viewforum.$phpEx", "f=$forum_id" . ((strlen($u_sort_param)) ? "&amp;$u_sort_param" : '')), $topics_count, $config['topics_per_page'], $start),
 	'PAGE_NUMBER'	=> on_page($topics_count, $config['topics_per_page'], $start),
 	'TOTAL_TOPICS'	=> ($s_display_active) ? false : (($topics_count == 1) ? $user->lang['VIEW_FORUM_TOPIC'] : sprintf($user->lang['VIEW_FORUM_TOPICS'], $topics_count)))
 );
diff --git a/phpBB/viewtopic.php b/phpBB/viewtopic.php
index 350aef2c11..d6ecf03c56 100644
--- a/phpBB/viewtopic.php
+++ b/phpBB/viewtopic.php
@@ -31,9 +31,13 @@ $voted_id	= request_var('vote_id', array('' => 0));
 $start		= request_var('start', 0);
 $view		= request_var('view', '');
 
-$sort_days	= request_var('st', ((!empty($user->data['user_post_show_days'])) ? $user->data['user_post_show_days'] : 0));
-$sort_key	= request_var('sk', ((!empty($user->data['user_post_sortby_type'])) ? $user->data['user_post_sortby_type'] : 't'));
-$sort_dir	= request_var('sd', ((!empty($user->data['user_post_sortby_dir'])) ? $user->data['user_post_sortby_dir'] : 'a'));
+$default_sort_days	= (!empty($user->data['user_post_show_days'])) ? $user->data['user_post_show_days'] : 0;
+$default_sort_key	= (!empty($user->data['user_post_sortby_type'])) ? $user->data['user_post_sortby_type'] : 't';
+$default_sort_dir	= (!empty($user->data['user_post_sortby_dir'])) ? $user->data['user_post_sortby_dir'] : 'a';
+
+$sort_days	= request_var('st', $default_sort_days);
+$sort_key	= request_var('sk', $default_sort_key);
+$sort_dir	= request_var('sd', $default_sort_dir);
 
 $update		= request_var('update', false);
 
@@ -388,7 +392,8 @@ $sort_by_text = array('a' => $user->lang['AUTHOR'], 't' => $user->lang['POST_TIM
 $sort_by_sql = array('a' => 'u.username_clean', 't' => 'p.post_time', 's' => 'p.post_subject');
 
 $s_limit_days = $s_sort_key = $s_sort_dir = $u_sort_param = '';
-gen_sort_selects($limit_days, $sort_by_text, $sort_days, $sort_key, $sort_dir, $s_limit_days, $s_sort_key, $s_sort_dir, $u_sort_param);
+
+gen_sort_selects($limit_days, $sort_by_text, $sort_days, $sort_key, $sort_dir, $s_limit_days, $s_sort_key, $s_sort_dir, $u_sort_param, $default_sort_days, $default_sort_key, $default_sort_dir);
 
 // Obtain correct post count and ordering SQL if user has
 // requested anything different
@@ -442,7 +447,7 @@ if ($start < 0 || $start > $total_posts)
 }
 
 // General Viewtopic URL for return links
-$viewtopic_url = append_sid("{$phpbb_root_path}viewtopic.$phpEx", "f=$forum_id&amp;t=$topic_id&amp;start=$start&amp;$u_sort_param" . (($highlight_match) ? "&amp;hilit=$highlight" : ''));
+$viewtopic_url = append_sid("{$phpbb_root_path}viewtopic.$phpEx", "f=$forum_id&amp;t=$topic_id&amp;start=$start" . ((strlen($u_sort_param)) ? "&amp;$u_sort_param" : '') . (($highlight_match) ? "&amp;hilit=$highlight" : ''));
 
 // Are we watching this topic?
 $s_watching_topic = array(
@@ -523,7 +528,7 @@ $topic_mod .= ($allow_change_type && $auth->acl_get('f_announce', $forum_id) &&
 $topic_mod .= ($auth->acl_get('m_', $forum_id)) ? '<option value="topic_logs">' . $user->lang['VIEW_TOPIC_LOGS'] . '</option>' : '';
 
 // If we've got a hightlight set pass it on to pagination.
-$pagination = generate_pagination(append_sid("{$phpbb_root_path}viewtopic.$phpEx", "f=$forum_id&amp;t=$topic_id&amp;$u_sort_param" . (($highlight_match) ? "&amp;hilit=$highlight" : '')), $total_posts, $config['posts_per_page'], $start);
+$pagination = generate_pagination(append_sid("{$phpbb_root_path}viewtopic.$phpEx", "f=$forum_id&amp;t=$topic_id" . ((strlen($u_sort_param)) ? "&amp;$u_sort_param" : '') . (($highlight_match) ? "&amp;hilit=$highlight" : '')), $total_posts, $config['posts_per_page'], $start);
 
 // Navigation links
 generate_forum_nav($topic_data);
@@ -557,7 +562,7 @@ $template->assign_vars(array(
 	'PAGINATION' 	=> $pagination,
 	'PAGE_NUMBER' 	=> on_page($total_posts, $config['posts_per_page'], $start),
 	'TOTAL_POSTS'	=> ($total_posts == 1) ? $user->lang['VIEW_TOPIC_POST'] : sprintf($user->lang['VIEW_TOPIC_POSTS'], $total_posts),
-	'U_MCP' 		=> ($auth->acl_get('m_', $forum_id)) ? append_sid("{$phpbb_root_path}mcp.$phpEx", "i=main&amp;mode=topic_view&amp;f=$forum_id&amp;t=$topic_id&amp;start=$start&amp;$u_sort_param", true, $user->session_id) : '',
+	'U_MCP' 		=> ($auth->acl_get('m_', $forum_id)) ? append_sid("{$phpbb_root_path}mcp.$phpEx", "i=main&amp;mode=topic_view&amp;f=$forum_id&amp;t=$topic_id&amp;start=$start" . ((strlen($u_sort_param)) ? "&amp;$u_sort_param" : ''), true, $user->session_id) : '',
 	'MODERATORS'	=> (isset($forum_moderators[$forum_id]) && sizeof($forum_moderators[$forum_id])) ? implode(', ', $forum_moderators[$forum_id]) : '',
 
 	'POST_IMG' 			=> ($topic_data['forum_status'] == ITEM_LOCKED) ? $user->img('button_topic_locked', 'FORUM_LOCKED') : $user->img('button_topic_new', 'POST_NEW_TOPIC'),