diff --git a/core/modules/php/php.module b/core/modules/php/php.module
index 37bf9a1..4c68abe 100644
--- a/core/modules/php/php.module
+++ b/core/modules/php/php.module
@@ -36,23 +36,26 @@ function php_permission() {
 }
 
 /**
- * Evaluate a string of PHP code.
+ * Implements hook_filter_FILTER_process().
  *
- * This is a wrapper around PHP's eval(). It uses output buffering to capture both
- * returned and printed text. Unlike eval(), we require code to be surrounded by
- * <?php ?> tags; in other words, we evaluate the code as if it were a stand-alone
- * PHP file.
+ * This is a wrapper around PHP's eval(). It uses output buffering to capture
+ * both returned and printed text. Unlike eval(), we require code to be
+ * surrounded by <?php ?> tags; in other words, we evaluate the code as if it
+ * were a stand-alone PHP file.
  *
  * Using this wrapper also ensures that the PHP code which is evaluated can not
  * overwrite any variables in the calling code, unlike a regular eval() call.
  *
  * @param $code
  *   The code to evaluate.
+ *
  * @return
- *   A string containing the printed output of the code, followed by the returned
- *   output of the code.
+ *   A string containing the printed output of the code, followed by the
+ *   returned output of the code.
  *
  * @ingroup php_wrappers
+ *
+ * @see php_filter_info()
  */
 function php_eval($code) {
   global $theme_path, $theme_info, $conf;
@@ -82,7 +85,9 @@ function php_eval($code) {
 }
 
 /**
- * Tips callback for php filter.
+ * Implements hook_filter_FILTER_tips().
+ *
+ * @see php_filter_info()
  */
 function _php_filter_tips($filter, $format, $long = FALSE) {
   global $base_url;
@@ -137,4 +142,3 @@ function php_filter_info() {
   );
   return $filters;
 }
-
diff --git a/core/modules/php/php.test b/core/modules/php/php.test
index 8ead2ac..50fb552 100644
--- a/core/modules/php/php.test
+++ b/core/modules/php/php.test
@@ -6,7 +6,7 @@
  */
 
 /**
- * Base PHP test case class.
+ * Defines a base PHP test case class.
  */
 class PHPTestCase extends DrupalWebTestCase {
   protected $php_code_format;
@@ -38,7 +38,7 @@ class PHPTestCase extends DrupalWebTestCase {
   }
 
   /**
-   * Create a test node with PHP code in the body.
+   * Creates a test node with PHP code in the body.
    *
    * @return stdObject Node object.
    */
@@ -60,7 +60,7 @@ class PHPFilterTestCase extends PHPTestCase {
   }
 
   /**
-   * Make sure that the PHP filter evaluates PHP code when used.
+   * Makes sure that the PHP filter evaluates PHP code when used.
    */
   function testPHPFilter() {
     // Log in as a user with permission to use the PHP code text format.
@@ -101,7 +101,7 @@ class PHPAccessTestCase extends PHPTestCase {
   }
 
   /**
-   * Make sure that user can't use the PHP filter when not given access.
+   * Makes sure that the user can't use the PHP filter when not given access.
    */
   function testNoPrivileges() {
     // Create node with PHP filter enabled.