diff --git a/boards/arm/s32k1xx/s32k118evb/README.txt b/boards/arm/s32k1xx/s32k118evb/README.txt
index 32b1b2aae00..1e9c468a160 100644
--- a/boards/arm/s32k1xx/s32k118evb/README.txt
+++ b/boards/arm/s32k1xx/s32k118evb/README.txt
@@ -29,6 +29,10 @@ Status
     changes, Fabio Balzano has verified that the NSH is functional on
     that board.
 
+  TODO:  Need calibrate the delay loop.  The current value of
+  CONFIG_BOARD_LOOPSPERMSEC is a bogus value retained from a copy-paste
+  (see apps/examples/calib_udelay).
+
 Serial Console
 ==============
 
diff --git a/boards/arm/s32k1xx/s32k146evb/README.txt b/boards/arm/s32k1xx/s32k146evb/README.txt
index 697daab288d..e3a43c63b64 100644
--- a/boards/arm/s32k1xx/s32k146evb/README.txt
+++ b/boards/arm/s32k1xx/s32k146evb/README.txt
@@ -35,6 +35,10 @@ Status
     on the S32K118, I believe that the NSH configuration should now run out
     of FLASH.  Unfortunately, I cannot demonstrate that.
 
+  TODO:  Need calibrate the delay loop.  The current value of
+  CONFIG_BOARD_LOOPSPERMSEC is a bogus value retained from a copy-paste
+  (see apps/examples/calib_udelay).
+
 Serial Console
 ==============
 
diff --git a/boards/arm/s32k1xx/s32k148evb/README.txt b/boards/arm/s32k1xx/s32k148evb/README.txt
index e15fa51532f..685861140e8 100644
--- a/boards/arm/s32k1xx/s32k148evb/README.txt
+++ b/boards/arm/s32k1xx/s32k148evb/README.txt
@@ -15,7 +15,12 @@ Contents
 Status
 ======
 
-  2019-08-20:  Configuration created but entirely untested.
+  2019-08-20:  NSH configuration created but entirely untested.
+  2019-08-24:  NSH configuratin verified running from FLASH.
+
+  TODO:  Need calibrate the delay loop.  The current value of
+  CONFIG_BOARD_LOOPSPERMSEC is a bogus value retained from a copy-paste
+  (see apps/examples/calib_udelay).
 
 Serial Console
 ==============
diff --git a/net/netdev/netdev.h b/net/netdev/netdev.h
index b1cf2572952..b1e3355a36b 100644
--- a/net/netdev/netdev.h
+++ b/net/netdev/netdev.h
@@ -159,16 +159,27 @@ FAR struct net_driver_s *netdev_findbyname(FAR const char *ifname);
  * Name: netdev_foreach
  *
  * Description:
- *   Enumerate each registered network device.
+ *   Enumerate each registered network device.  This function will terminate
+ *   when either (1) all devices have been enumerated or (2) when a callback
+ *   returns any non-zero value.
  *
- *   NOTE: netdev semaphore held throughout enumeration.
+ *   NOTE 1:  The network must be locked throughout the enumeration.
+ *   NOTE 2:  No checks are made on devices.  For examples, callbacks will
+ *            will be made on network devices that are in the 'down' state.
+ *            The callback implementations must take into account all
+ *            network device state.  Typically, a network in the down state
+ *            would not terminate the traversal.
  *
  * Input Parameters:
  *   callback - Will be called for each registered device
- *   arg      - User argument passed to callback()
+ *   arg      - Opaque user argument passed to callback()
  *
  * Returned Value:
- *  0:Enumeration completed 1:Enumeration terminated early by callback
+ *  0: Enumeration completed
+ *  1: Enumeration terminated early by callback
+ *
+ * Assumptions:
+ *  The network is locked.
  *
  ****************************************************************************/
 
diff --git a/net/netdev/netdev_foreach.c b/net/netdev/netdev_foreach.c
index 2309645328d..958e268e6e7 100644
--- a/net/netdev/netdev_foreach.c
+++ b/net/netdev/netdev_foreach.c
@@ -53,16 +53,24 @@
  * Name: netdev_foreach
  *
  * Description:
- *   Enumerate each registered network device.
+ *   Enumerate each registered network device.  This function will terminate
+ *   when either (1) all devices have been enumerated or (2) when a callback
+ *   returns any non-zero value.
  *
- *   NOTE: netdev semaphore held throughout enumeration.
+ *   NOTE 1:  The network must be locked throughout the enumeration.
+ *   NOTE 2:  No checks are made on devices.  For examples, callbacks will
+ *            will be made on network devices that are in the 'down' state.
+ *            The callback implementations must take into account all
+ *            network device state.  Typically, a network in the down state
+ *            would not terminate the traversal.
  *
  * Input Parameters:
  *   callback - Will be called for each registered device
- *   arg      - User argument passed to callback()
+ *   arg      - Opaque user argument passed to callback()
  *
  * Returned Value:
- *  0:Enumeration completed 1:Enumeration terminated early by callback
+ *  0: Enumeration completed
+ *  1: Enumeration terminated early by callback
  *
  * Assumptions:
  *  The network is locked.