Index: src/wp-includes/option.php
===================================================================
--- src/wp-includes/option.php	(revision 40364)
+++ src/wp-includes/option.php	(working copy)
@@ -1871,6 +1871,7 @@
  *     Data used to describe the setting when registered.
  *
  *     @type string   $type              The type of data associated with this setting.
+ *                                       Valid values are 'string', 'boolean', 'integer', and 'number'.
  *     @type string   $description       A description of the data attached to this setting.
  *     @type callable $sanitize_callback A callback function that sanitizes the option's value.
  *     @type bool     $show_in_rest      Whether data associated with this setting should be included in the REST API.