diff --git a/source/core/document.txt b/source/core/document.txt
index b64708718a2..6eb81f8cf82 100644
--- a/source/core/document.txt
+++ b/source/core/document.txt
@@ -249,7 +249,7 @@ The ``_id`` field has the following behavior and constraints:
   server receives a document that does not have the ``_id`` field
   first, then the server will move the field to the beginning.
 
-_ If the ``_id`` contains subfields, the subfield names cannot begin
+- If the ``_id`` contains subfields, the subfield names cannot begin
   with a (``$``) symbol.
 
 - The ``_id`` field may contain values of any :doc:`BSON data type