diff --git a/composer.json b/composer.json
index 356c195bfa..f5ee707263 100644
--- a/composer.json
+++ b/composer.json
@@ -65,7 +65,6 @@
             "themes/custom/{$name}": ["type:drupal-custom-theme"]
         },
         "drupal-core-project-message": {
-            "include-keys": ["homepage", "support"],
             "post-install-cmd-message": [
                 "<bg=blue;fg=white>drupal/drupal</>: This package is meant for core development,",
                 "               and not intended to be used for production sites.",
diff --git a/composer/Plugin/ProjectMessage/Config.php b/composer/Plugin/ProjectMessage/Message.php
similarity index 96%
rename from composer/Plugin/ProjectMessage/Config.php
rename to composer/Plugin/ProjectMessage/Message.php
index 246f064d16..b0cea11b92 100644
--- a/composer/Plugin/ProjectMessage/Config.php
+++ b/composer/Plugin/ProjectMessage/Message.php
@@ -7,12 +7,12 @@
 /**
  * Determine configuration.
  */
-class Config {
+class Message {
 
   /**
    * The root package.
    *
-   * @var Composer\Package\RootPackageInterface
+   * @var \Composer\Package\RootPackageInterface
    */
   protected $rootPackage;
 
@@ -43,7 +43,7 @@ public function __construct(RootPackageInterface $root_package, $event_name) {
     $this->eventName = $event_name;
   }
 
-  public function getMessageText() {
+  public function getText() {
     if ($this->messageText) {
       return $this->messageText;
     }
diff --git a/composer/Plugin/ProjectMessage/MessagePlugin.php b/composer/Plugin/ProjectMessage/MessagePlugin.php
index 9eddeb41e7..5e4f6614a5 100644
--- a/composer/Plugin/ProjectMessage/MessagePlugin.php
+++ b/composer/Plugin/ProjectMessage/MessagePlugin.php
@@ -54,8 +54,8 @@ public static function getSubscribedEvents() {
   }
 
   public function displayPostCreateMessage(Event $event) {
-    $config = new Config($this->composer->getPackage(), $event->getName());
-    if ($message = $config->getMessageText()) {
+    $message = new Message($this->composer->getPackage(), $event->getName());
+    if ($message = $message->getText()) {
       $this->io->write($message);
     }
   }
diff --git a/composer/Plugin/ProjectMessage/README.md b/composer/Plugin/ProjectMessage/README.md
index 5ad8ec0b7a..cbfc4ca7cc 100644
--- a/composer/Plugin/ProjectMessage/README.md
+++ b/composer/Plugin/ProjectMessage/README.md
@@ -21,8 +21,9 @@ processes have finished.
 This is ideal for a 'next steps' type prompt to help get the user oriented.
 
 Currently only two Composer events are supported:
-- post-create-project-cmd
-- post-install-cmd
+- post-create-project-cmd, when a `composer create-project` command has
+  finished.
+- post-install-cmd, when a `composer install` command has finished.
 
 How do I set it up?
 -------------------
@@ -37,8 +38,8 @@ Require this Composer plugin in your project template composer.json file:
 
 There are three ways to configure this plugin to output information:
 - Using a text file.
-- Embedding the information in the extra section of the composer.json file.
 - Using composer.json schema keys.
+- Embedding the information in the extra section of the composer.json file.
 
 ### Using a text file
 
@@ -62,11 +63,27 @@ composer.json file:
       }
     }
 
+### Using composer.json schema keys
+
+You can tell the plugin to output the structured support information from the
+composer.json file by telling it the keys you wish to display.
+
+Currently, only `name`, `description`, `homepage` and `support` are supported.
+
+    "extra": {
+        "drupal-core-project-message": {
+            "include-keys": ["homepage", "support"],
+        }
+    }
+
+Then you can include this information in your composer.json file, which you
+should probably be doing anyway.
+
 ### Embedding the information in the extra section
 
-In addition, you can specify text directly within the `extra` section by using
-the `-message` key. This message should be an array for each line, so that
-Composer can add the appropriate line ending character:
+You can specify text directly within the `extra` section by using the
+`[event-name]-message` key. This message should be an array, with one string for
+each line:
 
     "extra": {
       "drupal-core-project-message": {
@@ -77,16 +94,8 @@ Composer can add the appropriate line ending character:
       }
     }
 
-The `-message` section will always override `-file` for a given event.
-
-### Using composer.json schema keys
-
-You can tell the plugin to output the structured support information from the composer.json file by telling it the keys you wish to display.
-
-Currently, only `homepage` and `support` are supported.
+These strings should be plain text, with markup suitable for Symfony's
+`OutputInterface::writeln()` method. See documentation here:
+https://symfony.com/doc/3.4/console/coloring.html
 
-    "extra": {
-        "drupal-core-project-message": {
-            "include-keys": ["homepage", "support"],
-        }
-    }
+The `-message` section will always override `-file` for a given event.
diff --git a/core/tests/Drupal/Tests/Composer/Plugin/ProjectMessage/ConfigTest.php b/core/tests/Drupal/Tests/Composer/Plugin/ProjectMessage/ConfigTest.php
index 3481fdfcdc..a9a8eff6f6 100644
--- a/core/tests/Drupal/Tests/Composer/Plugin/ProjectMessage/ConfigTest.php
+++ b/core/tests/Drupal/Tests/Composer/Plugin/ProjectMessage/ConfigTest.php
@@ -3,12 +3,12 @@
 namespace Drupal\Tests\Composer\Plugin\ProjectMessage;
 
 use Composer\Package\RootPackageInterface;
-use Drupal\Composer\Plugin\ProjectMessage\Config;
+use Drupal\Composer\Plugin\ProjectMessage\Message;
 use PHPUnit\Framework\TestCase;
 use org\bovigo\vfs\vfsStream;
 
 /**
- * @coversDefaultClass Drupal\Composer\Plugin\ProjectMessage\Config
+ * @coversDefaultClass Drupal\Composer\Plugin\ProjectMessage\Message
  * @group ProjectMessage
  */
 class ConfigTest extends TestCase {
@@ -55,7 +55,7 @@ public function provideGetMessageText() {
 
   /**
    * @dataProvider provideGetMessageText
-   * @covers ::getMessageText
+   * @covers ::getText
    */
   public function testGetMessageText($expected, $config) {
     // Root package has our config.
@@ -66,13 +66,13 @@ public function testGetMessageText($expected, $config) {
       ->method('getExtra')
       ->willReturn($config);
 
-    $config = new Config($root, 'event-name');
+    $message = new Message($root, 'event-name');
 
-    $this->assertSame($expected, $config->getMessageText());
+    $this->assertSame($expected, $message->getText());
   }
 
   /**
-   * @covers ::getMessageText
+   * @covers ::getText
    */
   public function testDefaultFile() {
     // Root package has no extra field.
@@ -85,16 +85,16 @@ public function testDefaultFile() {
 
     // The default is to try to read from event-name-message.txt, so we expect
     // config to try that.
-    $config = $this->getMockBuilder(Config::class)
+    $message = $this->getMockBuilder(Message::class)
       ->setConstructorArgs([$root, 'event-name'])
       ->setMethods(['getMessageFromFile'])
       ->getMock();
-    $config->expects($this->once())
+    $message->expects($this->once())
       ->method('getMessageFromFile')
       ->with('event-name-message.txt')
       ->willReturn([]);
 
-    $this->assertSame([], $config->getMessageText());
+    $this->assertSame([], $message->getText());
   }
 
 }