anchor.diff:    version: 12.12.0
   ```
   
  -**Using package.json**
  +### <a id='package-json'></a> Using package.json
   
  -Applications using `npm` can specify the version of Node.js used during the
  -build and launch phases of their application deployment by configuring the
  -`engines` field in the `package.json` file. The following snippet in your
  -`package.json` will configure the buildpack to use `v12.12.0` of Node.js when
  -building and launching your application.
  +If your apps use `npm`, you can specify the Node.js version your apps use during deployment by configuring the `engines` field in the `package.json` file. To configure the buildpack to use Node.js v12.12.0 when deploying your app, include the values below in your `package.json` file:
   
   ```
   {
  
positive.code: * Value: path to the `node_modules` directory
  
  ### <a id="environment-variable-node-verbose"></a> NODE_VERBOSE
  Adjusts the amount of logging output from npm during installs
  
  * Set by: `node-engine-cnb`
  * Phases: `build`
  * Value: false
  
  ### <a id="environment-variable-npm-config-loglevel"></a> NPM\_CONFIG\_LOGLEVEL
  Level of logging npm will use
  
  * Set by: `node-engine-cnb`
  * Phases: `build`
  * Value: "error"
  
  ### <a id="environment-variable-npm-config-production"></a> NPM\_CONFIG\_PRODUCTION
  Install only production dependencies if NPM install is used
  
  * Set by: `node-engine-cnb`
  * Phases: `build`
  * Value: false
  
  ### <a id="environment-variable-path"></a> PATH
  Appends the `node_modules/.bin` directory onto the `$PATH`
  
  * Set by: `yarn-cnb`
  * Phases: `build`
  * Value: path to the `node_modules/.bin` directory
  
  ##<a id="heap-memory-optimization"></a> Heap Memory Optimization
  
  Node.js will limit the total size of all objects on the heap. Enabling the
  "optimize-memory" feature will set this value to 3/4 of the total memory
  available in the container. For example, if my app is limited to 1GB when
  pushed, the heap of my Node.js application will be limited to 768MB.
  
  ###<a id="enabling-memory-optimization"></a> Enabling Memory Optimization
  **Using buildpack.yml**
  
  Add the following to your `buildpack.yml` file:
  
  ```
  ---
  
negative.code: }
  ```
  
  For more information about the `engines` configuration option in the `package.json` file, see the [engines](https://docs.npmjs.com/files/package.json#engines) section of the _npm-package.json_ topic in the NPM documentation.
  
  ### <a id='nvmrc'></a> Using .nvmrc
  
  Node Version Manager is a common option for managing the Node.js version an app uses. To specify the Node.js version your apps use during deployment, include a `.nvmrc` file with the version number. For more information about the contents of a `.nvmrc` file, see [.nvmrc](https://github.com/nvm-sh/nvm#nvmrc) in the Node Version Manager repository on GitHub.
  
  
  ## <a id="environment-variables"></a> Environment Variables
  
  The Node.js CNB sets a number of environment variables during the `build` and `launch` phases of the app lifecycle. The sectios below describe each environment variable, its impact on your app, and how to configure these variable with alternative settings.
  
  ### <a id="environment-variable-memory-available"></a> MEMORY_AVAILABLE
  
  The `MEMORY_AVAILABLE` environment variable reports the total amount of memory available to the app. The Node.js CNB calculates this value from the `$VCAP_APPLICATION` settings or the limits specified by the operating system in `/sys/fs/cgroup/memory/memory.limit_in_bytes`.
  
  * Set by: `profile.d`
  * Phases: `launch`
  * Value: non-negative integer
  
  ### <a id="environment-variable-node-env"></a> NODE_ENV
  
  * Set by: `node-engine-cnb`
  * Phases: `build`
  * Value: production
  
  ### <a id="environment-variable-node-home"></a> NODE_HOME
  
  * Set by: `node-engine-cnb`
  * Phases: `build`
  * Value: path to the `node` installation
  