anchor.diff:  
   #### PHP\_EXTENSIONS vs. ZEND\_EXTENSIONS
   
  -PHP has two kinds of extensions, "PHP extensions" and "Zend extensions". These [hook into the PHP executable in different ways](https://wiki.php.net/internals/extensions).
  +PHP has two kinds of extensions, _PHP extensions_ and _Zend extensions_. These hook into the PHP executable in different ways. See [https://wiki.php.net/internals/extensions](https://wiki.php.net/internals/extensions) for more information about the way extensions work internally in the engine.
   
  -For this reason, they are specified differently in ini files. Your app will fail if a Zend Extension is specified as a PHP Extension, or vice versa.
  +Because they hook into the PHP executable in different ways, they are specified differently in ini files. Apps fail if a Zend extension is specified as a PHP extension, or a PHP extension is specified as a Zend extension.
   
  -If you see this error:
  +If you see the following error, move the `example` extension from `extension` to `zend_extension`, then re-push your app:
   
   ```
   php-fpm | [warn-ioncube] The example Loader is a Zend-Engine extension and not a module (pid 40)
  
positive.code: php-fpm | NOTICE: PHP message: PHP Fatal error:  Unable to start example Loader module in Unknown on line 0
  ```
  
  Try moving the `example` extension from `extension` to `zend_extension`, then re-pushing your application.
  
  If you see this error:
  
  ```
  NOTICE: PHP message: PHP Warning:  example MUST be loaded as a Zend extension in Unknown on line 0
  ```
  
  Try moving the `example` extension from `zend_extension` to `extension`, then re-pushing your application.
  
  ### <a id="php-modules"></a> PHP Modules
  
  The following modules can be included by adding it to the `PHP_MODULES` list:
  
    - `cli`, installs `php` and `phar`
    - `fpm`, installs `PHP-FPM`
    - `cgi`, installs `php-cgi`
    - `pear`, installs Pear
  
    By default, the buildpack installs the `cli` module when you push a standalone application, and it installs the `fpm` module when you run a web application. You must specify `cgi` and `pear` if you want them installed.
  
  ## <a id="buildpack-extensions"></a>Buildpack Extensions
  
  The buildpack comes with extensions for its default behavior. These are the [HTTPD], [Nginx], [PHP], and [NewRelic] extensions.
  
  The buildpack is designed with an extension mechanism, allowing application developers to add behavior to the buildpack without modifying the buildpack code.
  
  When an application is pushed, the buildpack runs any extensions found in the `.extensions` directory of your application.
  
  The [Developer Documentation](https://github.com/cloudfoundry/php-buildpack/blob/master/README.md) explains how to write extensions.
  
  
negative.code: | NGINX\_VERSION               | Sets the version of Nginx to use. By default, the buildpack uses the latest stable version.                                                                                                                                                                                                                      |
  | PHP\_VERSION                 | Sets the version of PHP to use. <br> Set to a minor instead of a patch version, <br> such as `"{PHP_70_LATEST}"`. See [options.json](https://github.com/cloudfoundry/php-buildpack/blob/4f5e50fabf66c5840210cbc64fcd4068d8a27448/cf_spec/fixtures/php_app_using_php_7_latest/.bp-config/options.json).             |
  | PHP\_EXTENSIONS              | (DEPRECATED) A list of the [extensions](#php-extensions) to enable.  `bz2`, `zlib`, `curl`, and `mcrypt` are enabled by default.                                                                                                                                                                                                                                 |
  | PHP\_MODULES                 | A list of the [modules](#php-modules) to enable.  No modules are explicitly enabled by default, but the buildpack automatically chooses either `fpm` or `cli`. You can explicitly enable any or all of the following: `fpm`, `cli`, `cgi`, and `pear`.                                                                                           |
  | ZEND\_EXTENSIONS             | A list of the Zend extensions to enable. Nothing is enabled by default.                                                                                                                                                                                                                                                                           |
  | APP\_START\_CMD              | When the `WEB_SERVER` option is set to `none`, this command is used to start your app. If `WEB_SERVER` and `APP_START_CMD` are not set, then the buildpack searches, in order, for `app.php`, `main.php`, `run.php`, or `start.php`. This option accepts arguments. |
  | WEBDIR                       | The root directory of the files served by the web server specified in `WEB_SERVER`. Defaults to `htdocs`. Other common settings are `public`, `static`, or `html`. The path is relative to the root of your application.           |
  | LIBDIR                       | This path is added to PHP's `include_path`. Defaults to `lib`. The path is relative to the root of your application.           |
  | HTTP\_PROXY                  | The buildpack downloads uncached dependencies using HTTP. If you are using a proxy for HTTP access, set its URL here.
  | HTTPS\_PROXY                  | The buildpack downloads uncached dependencies using HTTPS. If you are using a proxy for HTTPS access, set its URL here.
  | ADDITIONAL\_PREPROCESS\_CMDS | A list of additional commands that run prior to the application starting. For example, you might use this command to run migration scripts or static caching tools before the application launches.
  
  For details about supported versions, see the [release notes](https://github.com/cloudfoundry/php-buildpack/releases) for your buildpack version.
  
  ### <a id="engine-configurations"></a> HTTPD, Nginx, and PHP configuration
  
  The buildpack automatically configures HTTPD, Nginx, and PHP for your application.  This section explains how to modify the configuration.
  
  The `.bp-config` directory in your application can contain configuration overrides for these components. Name the directories `httpd`, `nginx`, and `php`. We recommend that you use [php.ini.d](#php_ini_d) or [fpm.d](#fpm_d).
  
  <p class='note'><strong>NOTE</strong>: If you override the <code>php.ini</code> or <code>php-fpm.ini</code> files, many other forms of configuration will not work.</p>
  
  For example:
  ```
  