diff --git a/dsdl/uavcan/equipment/gnss/300.Fix.uavcan b/dsdl/uavcan/equipment/gnss/300.Fix.uavcan
index 8e3997307e..2613365065 100644
--- a/dsdl/uavcan/equipment/gnss/300.Fix.uavcan
+++ b/dsdl/uavcan/equipment/gnss/300.Fix.uavcan
@@ -4,8 +4,22 @@
 
 uavcan.Timestamp timestamp         # Global network-synchronized time, if available, otherwise zero
 
-uavcan.Timestamp gnss_timestamp    # GNSS timestamp (UTC is preferred), if available, otherwise zero
+#
+# Time solution
+#
+# The following rules apply:
+#  - if num_leap_seconds is zero, it is assumed that its value is unknown, and that gnss_timestamp contains GPS time.
+#  - if num_leap_seconds is nonzero, it is assumed that its value is known, and that gnss_timestamp contains UTC time.
+#
+# At the time of February 2015, the number of leap seconds is 26.
+#
+uavcan.Timestamp gnss_timestamp    # GNSS timestamp, if available, otherwise zero
 
+uint8 num_leap_seconds
+
+#
+# Position and velocity solution
+#
 int37 longitude_deg_1e8            # Longitude degrees multiplied by 1e8 (approx. 1 mm per LSB)
 int37 latitude_deg_1e8             # Latitude degrees multiplied by 1e8 (approx. 1 mm per LSB on equator)
 int27 height_ellipsoid_mm          # Height above ellipsoid in millimeters
@@ -13,6 +27,9 @@ int27 height_msl_mm                # Height above mean sea level in millimeters
 
 float16[3] ned_velocity            # NED frame (north-east-down) in meters per second
 
+#
+# Fix status
+#
 uint6 sats_used
 
 uint2 STATUS_NO_FIX    = 0
@@ -21,6 +38,9 @@ uint2 STATUS_2D_FIX    = 2
 uint2 STATUS_3D_FIX    = 3
 uint2 status
 
+#
+# Precision
+#
 float16 pdop
 
 float16[<=9] position_covariance   # m^2
diff --git a/dsdl/uavcan/equipment/gnss/302.Auxiliary.uavcan b/dsdl/uavcan/equipment/gnss/302.Auxiliary.uavcan
index 6321bca887..43bb3c56be 100644
--- a/dsdl/uavcan/equipment/gnss/302.Auxiliary.uavcan
+++ b/dsdl/uavcan/equipment/gnss/302.Auxiliary.uavcan
@@ -13,5 +13,3 @@ float16 edop
 
 uint7 sats_visible                    # All visible sats of all available GNSS (e.g. GPS, GLONASS, etc)
 uint6 sats_used                       # All used sats of all available GNSS
-
-bool differential_corrections_applied