diff --git a/includes/common.inc b/includes/common.inc
index f6171cf..5e7db03 100644
--- a/includes/common.inc
+++ b/includes/common.inc
@@ -2077,6 +2077,8 @@ function _format_date_callback(array $matches = NULL, $new_langcode = NULL) {
 }
 
 /**
+ * Implements callback_entity_info_label().
+ *
  * Format a username.
  *
  * By default, the passed-in object's 'name' property is used if it exists, or
diff --git a/modules/comment/comment.module b/modules/comment/comment.module
index 46115be..a83069f 100644
--- a/modules/comment/comment.module
+++ b/modules/comment/comment.module
@@ -152,7 +152,7 @@ function comment_node_type_load($name) {
 }
 
 /**
- * Entity URI callback.
+ * Implements callback_entity_info_uri().
  */
 function comment_uri($comment) {
   return array(
diff --git a/modules/field/tests/field_test.module b/modules/field/tests/field_test.module
index 37ea7b1..3bdd64d 100644
--- a/modules/field/tests/field_test.module
+++ b/modules/field/tests/field_test.module
@@ -204,7 +204,7 @@ function field_test_dummy_field_storage_query(EntityFieldQuery $query) {
 }
 
 /**
- * Entity label callback.
+ * Implements callback_entity_info_label().
  *
  * @param $entity
  *   The entity object.
diff --git a/modules/forum/forum.module b/modules/forum/forum.module
index fe0ef79..e4d5194 100644
--- a/modules/forum/forum.module
+++ b/modules/forum/forum.module
@@ -233,6 +233,8 @@ function forum_entity_info_alter(&$info) {
 }
 
 /**
+ * Implements callback_entity_info_uri().
+ *
  * Entity URI callback used in forum_entity_info_alter().
  */
 function forum_uri($forum) {
diff --git a/modules/node/node.module b/modules/node/node.module
index 533365b..c13c49b 100644
--- a/modules/node/node.module
+++ b/modules/node/node.module
@@ -243,7 +243,7 @@ function node_field_display_node_alter(&$display, $context) {
 }
 
 /**
- * Entity URI callback.
+ * Implements callback_entity_info_uri().
  *
  * @param $node
  *   A node entity.
diff --git a/modules/system/system.api.php b/modules/system/system.api.php
index 195bc83..f5413c9 100644
--- a/modules/system/system.api.php
+++ b/modules/system/system.api.php
@@ -84,21 +84,23 @@ function hook_hook_info_alter(&$hooks) {
  *     Defaults to TRUE.
  *   - load hook: The name of the hook which should be invoked by
  *     DrupalDefaultEntityController:attachLoad(), for example 'node_load'.
- *   - uri callback: A function taking an entity as argument and returning the
- *     URI elements of the entity, e.g. 'path' and 'options'. The actual entity
- *     URI can be constructed by passing these elements to url().
- *   - label callback: (optional) A function taking an entity and an entity type
- *     as arguments and returning the label of the entity. The entity label is
- *     the main string associated with an entity; for example, the title of a
- *     node or the subject of a comment. If there is an entity object property
- *     that defines the label, use the 'label' element of the 'entity keys'
- *     return value component to provide this information (see below). If more
- *     complex logic is needed to determine the label of an entity, you can
- *     instead specify a callback function here, which will be called to
- *     determine the entity label. See also the entity_label() function, which
- *     implements this logic.
- *   - language callback: (optional) A function taking an entity and an entity
- *     type as arguments and returning a language code. In most situations, when
+ *   - uri callback: The name of an implementation of callback_entity_info_uri()
+ *     which takes the entity as argument and returns the URI elements of the
+ *     entity, e.g. 'path' and 'options'. The actual entity URI can be
+ *     constructed by passing these elements to url().
+ *   - label callback: (optional) The name of an implementation of
+ *     callback_entity_info_label(), which returns the label of the entity. The
+ *     entity label is the main string associated with an entity; for example,
+ *     the title of a node or the subject of a comment. If there is an entity
+ *     object property that defines the label, use the 'label' element of the
+ *     'entity keys' return value component to provide this information (see
+ *     below). If more complex logic is needed to determine the label of an
+ *     entity, you can instead specify a callback function here, which will be
+ *     called to determine the entity label. See also the entity_label()
+ *     function, which implements this logic.
+ *   - language callback: (optional) The name of an implementation of
+ *     callback_entity_info_language(), which takes an entity and an entity
+ *     type as arguments and returns a language code. In most situations, when
  *     needing to determine this value, inspecting a property named after the
  *     'language' element of the 'entity keys' should be enough. The language
  *     callback is meant to be used primarily for temporary alterations of the
@@ -2302,7 +2304,7 @@ function hook_theme_registry_alter(&$theme_registry) {
  * @return
  *   The machine-readable name of the theme that should be used for the current
  *   page request. The value returned from this function will only have an
- *   effect if it corresponds to a currently-active theme on the site. Do not 
+ *   effect if it corresponds to a currently-active theme on the site. Do not
  *   return a value if you do not wish to set a custom theme.
  */
 function hook_custom_theme() {
@@ -3638,7 +3640,7 @@ function hook_registry_files_alter(&$files, $modules) {
  * inspect later. It is important to remove any temporary variables using
  * variable_del() before your last task has completed and control is handed
  * back to the installer.
- * 
+ *
  * @param array $install_state
  *   An array of information about the current installation state.
  *
@@ -4689,6 +4691,66 @@ function hook_filetransfer_info_alter(&$filetransfer_info) {
  */
 
 /**
+ * @addtogroup callbacks
+ * @{
+ */
+
+/**
+ * Returns the URI for an entity.
+ *
+ * Callback for hook_entity_info().
+ *
+ * @param $entity
+ *  The entity to return the URI for.
+ *
+ * @return
+ *  An associative array with element 'path' giving the URL path, and 'options'
+ *  giving options for the url() function. The actual entity URI can be
+ *  constructed by passing these elements to url()
+ */
+function callback_entity_info_uri($entity) {
+  return array(
+    'path' => 'node/' . $entity->nid,
+  );
+}
+
+/**
+ * Returns the label of an entity.
+ *
+ * Callback for hook_entity_info().
+ *
+ * @param $entity
+ *  The entity for which to generate the label.
+ * @param $entity_type
+ *  The entity type; e.g., 'node' or 'user'.
+ *
+ * @see entity_label()
+ */
+function callback_entity_info_label($entity, $entity_type) {
+  return empty($entity->title) ? 'Untitled entity' : $entity->title;
+}
+
+/**
+ * Returns the language of the entity.
+ *
+ * Callback for hook_entity_info().
+ *
+ * @param $entity
+ *  The entity for which to generate the label.
+ * @param $entity_type
+ *  The entity type; e.g., 'node' or 'user'.
+ *
+ * @see entity_language()
+ */
+function callback_entity_info_language ($entity, $entity_type) {
+  return $entity->language;
+}
+
+/**
+ * @} End of "addtogroup callbacks".
+ */
+
+/**
  * @defgroup update_api Update versions of API functions
  * @{
  * Functions that are similar to normal API functions, but do not invoke hooks.
diff --git a/modules/taxonomy/taxonomy.module b/modules/taxonomy/taxonomy.module
index 9be7dfc..7ad28e9 100644
--- a/modules/taxonomy/taxonomy.module
+++ b/modules/taxonomy/taxonomy.module
@@ -140,7 +140,7 @@ function taxonomy_entity_info() {
 }
 
 /**
- * Entity URI callback.
+ * Implements callback_entity_info_uri().
  */
 function taxonomy_term_uri($term) {
   return array(
diff --git a/modules/user/user.module b/modules/user/user.module
index c1c7ec2..bff6f76 100644
--- a/modules/user/user.module
+++ b/modules/user/user.module
@@ -187,7 +187,7 @@ function user_entity_info() {
 }
 
 /**
- * Entity URI callback.
+ * Implements callback_entity_info_uri().
  */
 function user_uri($user) {
   return array(