diff --git a/source/reference/mongodb-extended-json.txt b/source/reference/mongodb-extended-json.txt
index f89ee3bab25..bdb85c87e36 100644
--- a/source/reference/mongodb-extended-json.txt
+++ b/source/reference/mongodb-extended-json.txt
@@ -97,9 +97,9 @@ Binary
 
 - ``<bindata>`` is the base64 representation of a binary string.
 
-- ``<t>`` is the hexadecimal representation of a single byte that
-  indicates the data type.  See the extended bson documentation.
-  http://bsonspec.org/spec.html
+- ``<t>`` is a representation of a single byte indicating the data type. In
+  *Strict mode* it is a hexadecimal string, and in *Shell mode* it is an integer.
+  See the extended bson documentation. http://bsonspec.org/spec.html
 
 Date
 ~~~~