diff -r 346c88efed21 -r 5e2f62d02dcd wp/wp-includes/post-thumbnail-template.php
--- a/wp/wp-includes/post-thumbnail-template.php	Mon Jun 08 16:11:51 2015 +0000
+++ b/wp/wp-includes/post-thumbnail-template.php	Tue Jun 09 03:35:32 2015 +0200
@@ -2,8 +2,8 @@
 /**
  * WordPress Post Thumbnail Template Functions.
  *
- * Support for post thumbnails
- * Themes function.php must call add_theme_support( 'post-thumbnails' ) to use these.
+ * Support for post thumbnails.
+ * Theme's functions.php must call add_theme_support( 'post-thumbnails' ) to use these.
  *
  * @package WordPress
  * @subpackage Template
@@ -35,12 +35,22 @@
 }
 
 /**
- * Display Post Thumbnail.
+ * Display the post thumbnail.
+ *
+ * When a theme adds 'post-thumbnail' support, a special 'post-thumbnail' image size
+ * is registered, which differs from the 'thumbnail' image size managed via the
+ * Settings > Media screen.
+ *
+ * When using the_post_thumbnail() or related functions, the 'post-thumbnail' image
+ * size is used by default, though a different size can be specified instead as needed.
  *
  * @since 2.9.0
  *
- * @param string|array $size Optional. Image size. Defaults to 'post-thumbnail', which theme sets using set_post_thumbnail_size( $width, $height, $crop_flag );.
- * @param string|array $attr Optional. Query string or array of attributes.
+ * @see get_the_post_thumbnail()
+ *
+ * @param string|array $size Optional. Registered image size to use, or flat array of height
+ *                           and width values. Default 'post-thumbnail'.
+ * @param string|array $attr Optional. Query string or array of attributes. Default empty.
  */
 function the_post_thumbnail( $size = 'post-thumbnail', $attr = '' ) {
 	echo get_the_post_thumbnail( null, $size, $attr );
@@ -49,7 +59,7 @@
 /**
  * Update cache for thumbnails in the current loop
  *
- * @since 3.2
+ * @since 3.2.0
  *
  * @param object $wp_query Optional. A WP_Query instance. Defaults to the $wp_query global.
  */
@@ -74,13 +84,21 @@
 }
 
 /**
- * Retrieve Post Thumbnail.
+ * Retrieve the post thumbnail.
+ *
+ * When a theme adds 'post-thumbnail' support, a special 'post-thumbnail' image size
+ * is registered, which differs from the 'thumbnail' image size managed via the
+ * Settings > Media screen.
+ *
+ * When using the_post_thumbnail() or related functions, the 'post-thumbnail' image
+ * size is used by default, though a different size can be specified instead as needed.
  *
  * @since 2.9.0
  *
- * @param int $post_id Optional. Post ID.
- * @param string $size Optional. Image size. Defaults to 'post-thumbnail'.
- * @param string|array $attr Optional. Query string or array of attributes.
+ * @param int $post_id       Post ID. Default is the ID of the `$post` global.
+ * @param string|array $size Optional. Registered image size to use, or flat array of height
+ *                           and width values. Default 'post-thumbnail'.
+ * @param string|array $attr Optional. Query string or array of attributes. Default empty.
  */
 function get_the_post_thumbnail( $post_id = null, $size = 'post-thumbnail', $attr = '' ) {
 	$post_id = ( null === $post_id ) ? get_the_ID() : $post_id;