diff --git a/src/wp-includes/rest-api/class-wp-rest-request.php b/src/wp-includes/rest-api/class-wp-rest-request.php
index 4d4936b..9655321 100644
--- a/src/wp-includes/rest-api/class-wp-rest-request.php
+++ b/src/wp-includes/rest-api/class-wp-rest-request.php
@@ -16,6 +16,11 @@
  * used in that manner. It does not use ArrayObject (as we cannot rely on SPL),
  * so be aware it may have non-array behaviour in some cases.
  *
+ * Also, when using features provided by ArrayAccess, be aware your request
+ * values may not be those you expect them to be. In a request with GET id=1
+ * and POST id=2, $request['id'] will be 2, not 1. Use the more precise
+ * get_url_param(), get_body_param() and related methods when you need precision.
+ *
  * @since 4.4.0
  *
  * @see ArrayAccess