Index: src/wp-includes/user.php
===================================================================
--- src/wp-includes/user.php	(revision 49148)
+++ src/wp-includes/user.php	(working copy)
@@ -1617,8 +1617,9 @@
  * Conditional Tags} article in the Theme Developer Handbook.
  *
  * @since 2.1.0
+ * @since 5.6.0 Introduced `email_exists` filter.
  *
- * @param string $email Email.
+ * @param string $email The email to check for existence.
  * @return int|false The user ID on success, false on failure.
  */
 function email_exists( $email ) {
@@ -1636,7 +1637,7 @@
 	 *
 	 * @param int|false $user_id The user ID associated with the email,
 	 *                           or false if the email does not exist.
-	 * @param string    $email   Email.
+	 * @param string    $email   The email to check for existence.
 	 */
 	return apply_filters( 'email_exists', $user_id, $email );
 }