diff --git a/source/reference/sql-comparison.txt b/source/reference/sql-comparison.txt
index 4f108e22383..03f1b53f996 100644
--- a/source/reference/sql-comparison.txt
+++ b/source/reference/sql-comparison.txt
@@ -85,6 +85,14 @@ Select
 The following table presents the various SQL statements related to
 reading records from tables and the corresponding MongoDB statements.
 
+.. note:: 
+
+   The :method:`~db.collection.find()` method always includes the ``_id``
+   field in the returned documents unless specifically excluded through
+   :ref:`projection<projection>`. Some of the SQL queries below may include an
+   ``_id`` field to reflect this, even if the field is not included in the
+   corresponding :method:`~db.collection.find()` query.
+
 .. include:: /includes/table/sql-to-mongo-select-examples.rst
 
 For more information, see