DOCSP 29155 adding sort and uuids to mongosync page

source/reference/mongosync.txt

@@ -296,6 +296,26 @@ error occurs, the ``mongosync`` log may contain the word "error' but
 ``mongosync`` is still able to complete the sync. In the case that a
 sync does not complete, ``mongosync`` writes a fatal log entry. 
 
+UUIDs
+~~~~~
+
+``mongosync`` creates collections with new :abbr:`UUIDs (universally
+unique identifiers)` on the destination cluster. There is no
+relationship between UUIDs on the source cluster and the destination
+cluster. If applications contain hard-coded UUIDs (which MongoDB does
+not recommend), you may need to update those applications before they
+work properly with the migrated cluster. 
+
+Sorting
+~~~~~~~
+
+``mongosync`` inserts documents on the destination cluster in an
+undefined order which does not preserve natural sort order from the
+source cluster. If applications depend on document order but don't have
+a defined sort method, you may need to update those applications to
+specify the expected sort order before the applications work properly
+with the migrated cluster. 
+
 .. _c2c-mongosync-examples:
 
 Examples