diff --git a/docs/manpages/nfdc-face.rst b/docs/manpages/nfdc-face.rst
index c00a6ce..c09191b 100644
--- a/docs/manpages/nfdc-face.rst
+++ b/docs/manpages/nfdc-face.rst
@@ -27,6 +27,8 @@
 The **nfdc face show** command shows properties and statistics of one specific face.
 
 The **nfdc face create** command creates a UDP unicast, TCP, or Ethernet unicast face.
+If the face already exists, the specified arguments will be used to update its properties, if
+possible.
 Local FaceUri is required for creating Ethernet unicast faces; otherwise it must be omitted.
 The NDNLPv2 unicast reliability feature may be explicitly enabled by specifying **reliability on**
 or explicitly disabled by specifying **reliability off**.
@@ -38,11 +40,10 @@
 default on all other face types.
 Parameters for this feature can set with the **congestion-marking-interval** option (specified in
 milliseconds) and the **default-congestion-threshold** option (specified in bytes).
-The MTUs of unicast Ethernet and UDP faces may be overridden using the **mtu** parameter (specified
-in bytes).
-However, a face may choose to limit the range of acceptable values for this parameter or disregard
-it altogether when setting its MTU.
-The MTU of an existing face may not be modified using this parameter and will result in an error.
+The effective MTUs of unicast Ethernet and UDP faces may be overridden using the **mtu** parameter
+(specified in bytes).
+The forwarder may limit the range of this override MTU and will use the minimum of it and the MTU
+of the underlying Ethernet or UDP transport.
 
 The **nfdc face destroy** command destroys an existing face.
 
@@ -93,6 +94,12 @@
     It is the maximum bound of the congestion threshold for the face, as well as the default
     threshold used if the face does not support retrieving the capacity of the send queue.
 
+<MTU>
+    The MTU used to override the MTU of the underlying transport on Ethernet and UDP faces.
+    This MTU serves as an upper bound for the MTU provided by the transport.
+    The range of acceptable values may be limited by the forwarder.
+    To unset this override, specify the MTU as "auto".
+
 EXIT CODES
 ----------
 0: Success
@@ -135,8 +142,7 @@
     Create a face with the specified remote FaceUri and explicitly disable congestion marking.
 
 nfdc face create remote udp://router.example.net mtu 4000
-    Create a face with the specified remote FaceUri and an MTU of 4000 bytes (which may be ignored
-    or limited to within a certain range by the internal logic of the face).
+    Create a face with the specified remote FaceUri and set the override MTU to 4000 bytes.
 
 nfdc face destroy 300
     Destroy the face whose FaceId is 300.