diff --git a/src/wp-includes/version.php b/src/wp-includes/version.php
index 9965b10a72..27e14721a9 100644
--- a/src/wp-includes/version.php
+++ b/src/wp-includes/version.php
@@ -11,6 +11,9 @@
 /**
  * The WordPress version string.
  *
+ * Holds the current version number for WordPress core. Used to bust caches
+ * and to enable development mode for scripts when running from the /src directory.
+ *
  * @global string $wp_version
  */
 $wp_version = '5.9-alpha-51272-src';