diff --git a/includes/theme.inc b/includes/theme.inc
index e50df06..99cf43b 100644
--- a/includes/theme.inc
+++ b/includes/theme.inc
@@ -9,32 +9,6 @@
  */
 
 /**
- * @defgroup content_flags Content markers
- * @{
- * Markers used by theme_mark() and node_mark() to designate content.
- * @see theme_mark(), node_mark()
- */
-
-/**
- * Mark content as read.
- */
-define('MARK_READ', 0);
-
-/**
- * Mark content as being new.
- */
-define('MARK_NEW', 1);
-
-/**
- * Mark content as being updated.
- */
-define('MARK_UPDATED', 2);
-
-/**
- * @} End of "Content markers".
- */
-
-/**
  * Determines if a theme is available to use.
  *
  * @param $theme
@@ -1921,19 +1895,13 @@ function theme_tablesort_indicator($variables) {
  *
  * @param $variables
  *   An associative array containing:
- *   - type: Number representing the marker type to display. See MARK_NEW,
- *     MARK_UPDATED, MARK_READ.
+ *   - type: String representing the marker type to display.
  */
 function theme_mark($variables) {
   $type = $variables['type'];
   global $user;
-  if ($user->uid) {
-    if ($type == MARK_NEW) {
-      return ' <span class="marker">' . t('new') . '</span>';
-    }
-    elseif ($type == MARK_UPDATED) {
-      return ' <span class="marker">' . t('updated') . '</span>';
-    }
+  if ($user->uid && $type != '') {
+    return ' <mark>' . t($type) . '</mark>';
   }
 }
 
diff --git a/misc/farbtastic/farbtastic.css b/misc/farbtastic/farbtastic.css
index 25a68eb..334cc8d 100644
--- a/misc/farbtastic/farbtastic.css
+++ b/misc/farbtastic/farbtastic.css
@@ -26,7 +26,7 @@
 .farbtastic .overlay {
   background: url(mask.png) no-repeat;
 }
-.farbtastic .marker {
+.farbtastic mark {
   width: 17px;
   height: 17px;
   margin: -8px 0 0 -8px;
diff --git a/modules/node/node.module b/modules/node/node.module
index 0c3cfb7..b565990 100644
--- a/modules/node/node.module
+++ b/modules/node/node.module
@@ -336,25 +336,25 @@ function node_last_viewed($nid) {
  * @param $timestamp
  *   Time which is compared against node's "last viewed" timestamp.
  * @return
- *   One of the MARK constants.
+ *   String indicating the marker to be displayed.
  */
 function node_mark($nid, $timestamp) {
   global $user;
   $cache = &drupal_static(__FUNCTION__, array());
 
   if (!$user->uid) {
-    return MARK_READ;
+    return '';
   }
   if (!isset($cache[$nid])) {
     $cache[$nid] = node_last_viewed($nid);
   }
   if ($cache[$nid] == 0 && $timestamp > NODE_NEW_LIMIT) {
-    return MARK_NEW;
+    return 'new';
   }
   elseif ($timestamp > $cache[$nid] && $timestamp > NODE_NEW_LIMIT) {
-    return MARK_UPDATED;
+    return 'updated';
   }
-  return MARK_READ;
+  return '';
 }
 
 /**
diff --git a/modules/system/system.theme.css b/modules/system/system.theme.css
index f34a965..194c952 100644
--- a/modules/system/system.theme.css
+++ b/modules/system/system.theme.css
@@ -100,7 +100,7 @@ input.form-checkbox,
 input.form-radio {
   vertical-align: middle;
 }
-.marker,
+
 .form-required {
   color: #f00;
 }
diff --git a/themes/seven/reset.css b/themes/seven/reset.css
index 306b1f9..c03cb1b 100644
--- a/themes/seven/reset.css
+++ b/themes/seven/reset.css
@@ -59,6 +59,7 @@ li,
 fieldset,
 form,
 input,
+mark,
 select,
 textarea,
 label,
@@ -102,7 +103,6 @@ tr.even .form-item,
 .form-radios,
 .form-checkboxes .form-item,
 .form-radios .form-item,
-.marker,
 .form-required,
 .more-link,
 .more-help-link,