diff --git a/wp-admin/options-permalink.php b/wp-admin/options-permalink.php
index 8a68a4699..f71e6058f 100644
--- a/wp-admin/options-permalink.php
+++ b/wp-admin/options-permalink.php
@@ -73,10 +73,18 @@ if ( isset($_POST['permalink_structure']) || isset($_POST['category_base']) ) {
 			$category_base = preg_replace('#/+#', '/', '/' . $_POST['category_base']);
 		$wp_rewrite->set_category_base($category_base);
 	}
+
+	if ( isset($_POST['tag_base']) ) {
+		$tag_base = $_POST['tag_base'];
+		if (! empty($tag_base) )
+			$tag_base = preg_replace('#/+#', '/', '/' . $_POST['tag_base']);
+		$wp_rewrite->set_tag_base($tag_base);
+	}
 }
 
 $permalink_structure = get_option('permalink_structure');
 $category_base = get_option('category_base');
+$tag_base = get_option( 'tag_base' );
 
 if ( (!file_exists($home_path.'.htaccess') && is_writable($home_path)) || is_writable($home_path.'.htaccess') )
 	$writable = true;
@@ -159,6 +167,9 @@ checked="checked"
 <?php endif; ?>
 	<p> 
   <?php _e('Category base'); ?>: <input name="category_base" type="text" class="code"  value="<?php echo attribute_escape($category_base); ?>" size="30" /> 
+     </p>
+	  <p>
+	  <?php _e('Tag base'); ?>: <input name="tag_base" type="text" class="code"  value="<?php echo attribute_escape($tag_base); ?>" size="30" /> 
      </p> 
     <p class="submit"> 
       <input type="submit" name="submit" value="<?php _e('Update Permalink Structure &raquo;') ?>" /> 
diff --git a/wp-admin/upgrade-schema.php b/wp-admin/upgrade-schema.php
index a41ca9479..e6a4a0599 100644
--- a/wp-admin/upgrade-schema.php
+++ b/wp-admin/upgrade-schema.php
@@ -242,6 +242,9 @@ function populate_options() {
 	add_option('default_link_category', 2);
 	add_option('show_on_front', 'posts');
 
+	// 2.2
+	add_option('tag_base');
+
 	// Delete unused options
 	$unusedoptions = array ('blodotgsping_url', 'bodyterminator', 'emailtestonly', 'phoneemail_separator', 'smilies_directory', 'subjectprefix', 'use_bbcode', 'use_blodotgsping', 'use_phoneemail', 'use_quicktags', 'use_weblogsping', 'weblogs_cache_file', 'use_preview', 'use_htmltrans', 'smilies_directory', 'fileupload_allowedusers', 'use_phoneemail', 'default_post_status', 'default_post_category', 'archive_mode', 'time_difference', 'links_minadminlevel', 'links_use_adminlevels', 'links_rating_type', 'links_rating_char', 'links_rating_ignore_zero', 'links_rating_single_image', 'links_rating_image0', 'links_rating_image1', 'links_rating_image2', 'links_rating_image3', 'links_rating_image4', 'links_rating_image5', 'links_rating_image6', 'links_rating_image7', 'links_rating_image8', 'links_rating_image9', 'weblogs_cacheminutes', 'comment_allowed_tags', 'search_engine_friendly_urls', 'default_geourl_lat', 'default_geourl_lon', 'use_default_geourl', 'weblogs_xml_url', 'new_users_can_blog', '_wpnonce', '_wp_http_referer', 'Update', 'action', 'rich_editing');
 	foreach ($unusedoptions as $option) :
diff --git a/wp-includes/category-template.php b/wp-includes/category-template.php
index 25b66edbe..ebb4da944 100644
--- a/wp-includes/category-template.php
+++ b/wp-includes/category-template.php
@@ -42,7 +42,7 @@ function get_category_link($category_id) {
 
 function get_tag_link( $tag_id ) {
 	global $wp_rewrite;
-	$catlink = $wp_rewrite->get_category_permastruct();
+	$catlink = $wp_rewrite->get_tag_permastruct();
 
 	$category = &get_category($tag_id);
 	$category_nicename = $category->category_nicename;
diff --git a/wp-includes/functions.php b/wp-includes/functions.php
index 65b4aa816..74c2ccb94 100644
--- a/wp-includes/functions.php
+++ b/wp-includes/functions.php
@@ -670,7 +670,7 @@ function update_post_category_cache($post_ids) {
 }
 
 function update_post_caches(&$posts) {
-	global $post_cache, $category_cache, $post_meta_cache;
+	global $post_cache, $category_cache, $post_meta_cache, $tag_cache;
 	global $wpdb, $blog_id;
 
 	// No point in doing all this work if we didn't match any posts.
diff --git a/wp-includes/link-template.php b/wp-includes/link-template.php
index a7f9601d3..d5049f841 100644
--- a/wp-includes/link-template.php
+++ b/wp-includes/link-template.php
@@ -59,6 +59,7 @@ function get_permalink($id = 0) {
 		'%postname%',
 		'%post_id%',
 		'%category%',
+		'%tag%',
 		'%author%',
 		'%pagename%'
 	);
diff --git a/wp-includes/rewrite.php b/wp-includes/rewrite.php
index a1e0db7e0..125f91217 100644
--- a/wp-includes/rewrite.php
+++ b/wp-includes/rewrite.php
@@ -46,11 +46,12 @@ define('EP_ROOT',       64  );
 define('EP_COMMENTS',   128 );
 define('EP_SEARCH',     256 );
 define('EP_CATEGORIES', 512 );
-define('EP_AUTHORS',    1024);
-define('EP_PAGES',      2048);
+define('EP_TAGS', 1024 );
+define('EP_AUTHORS',    2048);
+define('EP_PAGES',      4096);
 //pseudo-places
 define('EP_NONE',       0  );
-define('EP_ALL',        4095);
+define('EP_ALL',        8191);
 
 //and an endpoint, like /trackback/
 function add_rewrite_endpoint($name, $places) {
@@ -150,7 +151,9 @@ class WP_Rewrite {
 	var $permalink_structure;
 	var $use_trailing_slashes;
 	var $category_base;
+	var $tag_base;
 	var $category_structure;
+	var $tag_structure;
 	var $author_base = 'author';
 	var $author_structure;
 	var $date_structure;
@@ -181,6 +184,7 @@ class WP_Rewrite {
 					'%postname%',
 					'%post_id%',
 					'%category%',
+					'%tag%',
 					'%author%',
 					'%pagename%',
 					'%search%'
@@ -197,6 +201,7 @@ class WP_Rewrite {
 					'([^/]+)',
 					'([0-9]+)',
 					'(.+?)',
+					'(.+?)',
 					'([^/]+)',
 					'([^/]+)',
 					'(.+)'
@@ -213,6 +218,7 @@ class WP_Rewrite {
 					'name=',
 					'p=',
 					'category_name=',
+					'tag=',
 					'author_name=',
 					'pagename=',
 					's='
@@ -378,6 +384,26 @@ class WP_Rewrite {
 		return $this->category_structure;
 	}
 
+	function get_tag_permastruct() {
+		if (isset($this->tag_structure)) {
+			return $this->tag_structure;
+		}
+
+		if (empty($this->permalink_structure)) {
+			$this->tag_structure = '';
+			return false;
+		}
+
+		if (empty($this->tag_base))
+			$this->tag_structure = $this->front . 'tag/';
+		else
+			$this->tag_structure = $this->tag_base . '/';
+
+		$this->tag_structure .= '%tag%';
+
+		return $this->tag_structure;
+	}
+
 	function get_author_permastruct() {
 		if (isset($this->author_structure)) {
 			return $this->author_structure;
@@ -734,6 +760,10 @@ class WP_Rewrite {
 		$category_rewrite = $this->generate_rewrite_rules($this->get_category_permastruct(), EP_CATEGORIES);
 		$category_rewrite = apply_filters('category_rewrite_rules', $category_rewrite);
 
+		// Tags
+		$tag_rewrite = $this->generate_rewrite_rules($this->get_tag_permastruct(), EP_TAGS);
+		$tag_rewrite = apply_filters('tag_rewrite_rules', $tag_rewrite);
+
 		// Authors
 		$author_rewrite = $this->generate_rewrite_rules($this->get_author_permastruct(), EP_AUTHORS);
 		$author_rewrite = apply_filters('author_rewrite_rules', $author_rewrite);
@@ -743,7 +773,7 @@ class WP_Rewrite {
 		$page_rewrite = apply_filters('page_rewrite_rules', $page_rewrite);
 
 		// Put them together.
-		$this->rules = array_merge($robots_rewrite, $default_feeds, $page_rewrite, $root_rewrite, $comments_rewrite, $search_rewrite, $category_rewrite, $author_rewrite, $date_rewrite, $post_rewrite, $this->extra_rules);
+		$this->rules = array_merge($robots_rewrite, $default_feeds, $page_rewrite, $root_rewrite, $comments_rewrite, $search_rewrite, $category_rewrite, $tag_rewrite, $author_rewrite, $date_rewrite, $post_rewrite, $this->extra_rules);
 
 		do_action_ref_array('generate_rewrite_rules', array(&$this));
 		$this->rules = apply_filters('rewrite_rules_array', $this->rules);
@@ -869,7 +899,8 @@ class WP_Rewrite {
 		if ($this->using_index_permalinks()) {
 			$this->root = $this->index . '/';
 		}
-		$this->category_base = get_option('category_base');
+		$this->category_base = get_option( 'category_base' );
+		$this->tag_base = get_option( 'tag_base' );
 		unset($this->category_structure);
 		unset($this->author_structure);
 		unset($this->date_structure);
@@ -894,9 +925,16 @@ class WP_Rewrite {
 		}
 	}
 
+	function set_tag_base( $tag_base ) {
+		if ( $tag_base != $this->tag_base ) {
+			update_option( 'tag_base', $tag_base );
+			$this->init();
+		}
+	}
+
 	function WP_Rewrite() {
 		$this->init();
 	}
 }
 
-?>
+?>
\ No newline at end of file