diff --git a/sbp.cabal b/sbp.cabal
--- a/sbp.cabal
+++ b/sbp.cabal
@@ -1,5 +1,5 @@
 name:                  sbp
-version:               2.1.5
+version:               2.1.6
 synopsis:              SwiftNav's SBP Library
 homepage:              https://github.com/swift-nav/libsbp
 license:               LGPL-3
diff --git a/src/SwiftNav/SBP/Navigation.hs b/src/SwiftNav/SBP/Navigation.hs
--- a/src/SwiftNav/SBP/Navigation.hs
+++ b/src/SwiftNav/SBP/Navigation.hs
@@ -215,7 +215,7 @@
   , _msgPosEcef_z      :: Double
     -- ^ ECEF Z coordinate
   , _msgPosEcef_accuracy :: Word16
-    -- ^ Position accuracy estimate. Not implemented in SPP mode, defaults to 0.
+    -- ^ Position accuracy estimate.
   , _msgPosEcef_n_sats :: Word8
     -- ^ Number of satellites used in solution
   , _msgPosEcef_flags  :: Word8
@@ -270,11 +270,9 @@
   , _msgPosLlh_height   :: Double
     -- ^ Height above WGS84 ellipsoid
   , _msgPosLlh_h_accuracy :: Word16
-    -- ^ Horizontal position accuracy estimate. Not implemented in SPP mode,
-    -- defaults to 0.
+    -- ^ Horizontal position accuracy estimate.
   , _msgPosLlh_v_accuracy :: Word16
-    -- ^ Vertical position accuracy estimate. Not implemented in SPP mode,
-    -- defaults to 0.
+    -- ^ Vertical position accuracy estimate.
   , _msgPosLlh_n_sats   :: Word8
     -- ^ Number of satellites used in solution.
   , _msgPosLlh_flags    :: Word8
diff --git a/src/SwiftNav/SBP/Tracking.hs b/src/SwiftNav/SBP/Tracking.hs
--- a/src/SwiftNav/SBP/Tracking.hs
+++ b/src/SwiftNav/SBP/Tracking.hs
@@ -53,9 +53,8 @@
   , _msgTrackingStateDetailed_cn0        :: Word8
     -- ^ Carrier-to-Noise density
   , _msgTrackingStateDetailed_lock       :: Word16
-    -- ^ Lock indicator. This value changes whenever a satellite signal has lost
-    -- and regained lock, indicating that the carrier phase ambiguity may have
-    -- changed.
+    -- ^ Lock time. It is encoded according to DF402 from the RTCM 10403.2
+    -- Amendment 2 specification. Valid values range from 0 to 15.
   , _msgTrackingStateDetailed_sid        :: GnssSignal
     -- ^ GNSS signal identifier.
   , _msgTrackingStateDetailed_doppler    :: Int32