diff --git includes/theme.inc includes/theme.inc
index 44946cf..5145efc 100644
--- includes/theme.inc
+++ includes/theme.inc
@@ -1481,16 +1481,18 @@ function theme_links($variables) {
 }
 
 /**
- * Returns HTML for an image.
+ * Returns HTML for an image.  This function should never be called directly,
+ * but always as theme('image',$variables).
  *
  * @param $variables
  *   An associative array containing:
  *   - path: Either the path of the image file (relative to base_path()) or a
  *     full URL.
- *   - width: The width of the image (if known).
- *   - height: The height of the image (if known).
- *   - alt: The alternative text for text-based browsers. HTML 4 and XHTML 1.0
- *     always require an alt attribute. The HTML 5 draft allows the alt
+ *   - attributes: Associative array of attributes to be placed in the img tag.
+ *   - width: (optional) The width of the image (if known).
+ *   - height: (optional) The height of the image (if known).
+ *   - alt: (optional) The alternative text for text-based browsers. HTML 4 and
+ *     XHTML 1.0 always require an alt attribute. The HTML 5 draft allows the alt
  *     attribute to be omitted in some cases. Therefore, this variable defaults
  *     to an empty string, but can be set to NULL for the attribute to be
  *     omitted. Usually, neither omission nor an empty string satisfies
@@ -1499,9 +1501,8 @@ function theme_links($variables) {
  *     - http://www.w3.org/TR/REC-html40/struct/objects.html#h-13.8
  *     - http://www.w3.org/TR/xhtml1/dtds.html
  *     - http://dev.w3.org/html5/spec/Overview.html#alt
- *   - title: The title text is displayed when the image is hovered in some
- *     popular browsers.
- *   - attributes: Associative array of attributes to be placed in the img tag.
+ *   - title: (optional) The title text is displayed when the image is hovered
+ *     in some popular browsers.
  */
 function theme_image($variables) {
   $attributes = $variables['attributes'];