added note about REST params

Author: Kevin Harper

guides/v2.0/rest/notes.md

@@ -0,0 +1,24 @@
+---
+layout: default
+group: rest
+subgroup: A_rest
+title: Notes
+menu_title: Notes
+menu_order: 6
+version: 2.0
+github_link: rest/notes.md
+
+---
+
+## Parameters in URLs
+
+In a REST call, a user could potentially specify one ID in the URL and another in the request body. Whenever this type of conflict occurs, Magento uses the value specified in the URL.
+
+For example:
+
+The REST URL to update a customer is `<route url="/V1/customers/:id" method="PUT">`.  If you specify a ID value of `1` in the URL (`http://magento.loc/customer/1`), and a body of `{ “id”: 2, “attr”: “value” }`, the customer with ID of `1` will be modified.
+
+This applies to all REST APIs where a parameter is passed in the URL. Anything specified in the request body with the same parameter name as the URL will be ignored.
+
+## Related topics
+[Search using REST APIs]({{ site.gdeurl }}howdoi/webapi/search-criteria.html)