diff --git a/source/reference/configuration-options.txt b/source/reference/configuration-options.txt
index 2ad7bf6ed43..6badbd9d061 100644
--- a/source/reference/configuration-options.txt
+++ b/source/reference/configuration-options.txt
@@ -37,9 +37,10 @@ File Format
 
 .. versionchanged:: 2.6
 
-The configuration file is in `YAML <http://www.yaml.org>`_ format. For
-example, the following  contains various
-:program:`mongod` configuration settings in YAML format:
+MongoDB configuration files use the `YAML <http://www.yaml.org>`_ format
+[#yaml-json]_.
+The following example configuration file contains several
+:program:`mongod` settings:
 
 .. note::
 
@@ -63,6 +64,9 @@ example, the following  contains various
       enableLocalhostAuthBypass: false
    ...
 
+.. [#yaml-json] YAML is a superset of :term:`JSON` with syntax that is easier to
+   edit by hand.
+
 Use the Configuration File
 ~~~~~~~~~~~~~~~~~~~~~~~~~~
 
@@ -110,7 +114,7 @@ Core Options
       logRotate: <string>
       destination: <string>
       timeStampFormat: <string>
-      component: 
+      component:
          accessControl:
             verbosity: <int>
          command:
@@ -142,7 +146,7 @@ Core Options
 .. code-block:: yaml
 
    systemLog:
-      component: 
+      component:
          accessControl:
             verbosity: <int>
          command:
@@ -502,7 +506,7 @@ Core Options
    replication:
       oplogSizeMB: <int>
       replSetName: <string>
-      secondaryIndexPrefetch: <string> 
+      secondaryIndexPrefetch: <string>
 
 .. include:: /includes/option/setting-conf-replication.oplogSizeMB.rst
 
@@ -584,7 +588,7 @@ Windows Service Options
 .. code-block:: yaml
 
    processManagement:
-      windowsService: 
+      windowsService:
          serviceName: <string>
          displayName: <string>
          description: <string>