diff --git a/core/modules/views/lib/Drupal/views/Plugin/views/pager/PagerPluginBase.php b/core/modules/views/lib/Drupal/views/Plugin/views/pager/PagerPluginBase.php
index 1c877ff..508ce3c 100644
--- a/core/modules/views/lib/Drupal/views/Plugin/views/pager/PagerPluginBase.php
+++ b/core/modules/views/lib/Drupal/views/Plugin/views/pager/PagerPluginBase.php
@@ -21,6 +21,32 @@
 
 /**
  * The base plugin to handle pager.
+ *
+ * Pager plugins take care of everything regarding pagers, including getting
+ * setting the total number of items to render the pager and setting the global
+ * pager arrays.
+ *
+ * To define a pager type, extend this base class. The ViewsPluginManager (used to
+ * create views plugins objects) adds annotated discovery for block plugins. Your
+ * pager plugin should have an annotation that includes the plugin's metadata,
+ * for example:
+ * @Plugin(
+ *   id = "demo_pager",
+ *   title = @Translation("Display a demonstration pager"),
+ *   help = @Translation("Demonstrate pagination of views items."),
+ *   theme = "views_demo_pager"
+ * )
+ * The definition should include the following keys:
+ * - id: The unique identifier of your pager plugin.
+ * - type: The string "basic".
+ * - title: The "full" title for your pager type; the short_title is used in
+ *   the views UI when specified.
+ * - short_title: The "short" title for your pager type; this is displayed in
+ *   the views UI.
+ * - help: A short help string.
+ * - theme: The theme function used to render the pager's output.
+ *
+ * @see \Drupal\views\Plugin\ViewsPluginManager
  */
 abstract class PagerPluginBase extends PluginBase {