Index: trunk/BNS/bnshelp.html
===================================================================
--- trunk/BNS/bnshelp.html	(revision 2517)
+++ trunk/BNS/bnshelp.html	(revision 2536)
@@ -256,5 +256,5 @@
 <p><a name="co"><h4>4.5. Clocks &amp; Orbits</h4></p>
 <p>
-BNS requires GNSS clocks and orbits in the IGS Earth-Centered-Earth-Fixed (ECEF) reference system in a SP3-like format referred to CoM and not containing the 2nd order relativistic effect. They can be provided by a real-time GNSS engine such as RTNet. The sampling rate should not be much greater than 10 sec. Note that otherwise in IP streaming involved tools on the NTRIP Broadcaster or client side may respond with a timeout.
+BNS requires GNSS clocks and orbits in the IGS Earth-Centered-Earth-Fixed (ECEF) reference system in a SP3-like format referred to CoM and not containing the conventional periodic relativistic effect. They can be provided by a real-time GNSS engine such as RTNet. The sampling rate should not be much greater than 10 sec. Note that otherwise in IP streaming involved tools on the NTRIP Broadcaster or client side may respond with a timeout.
 </p>
 
@@ -268,5 +268,5 @@
 <li>X,Y,Z coordinates in Earth-Centered-Earth-Fixed system [km] at epoch T</li>
 <li>Satellite clock error [microsecond]</li>
-<li>2nd order relativistic effect [microsecond]</li>
+<li>Conventional periodic relativistic effect [microsecond]</li>
 <li>DX,DY,DZ [m] in Earth-Centered-Earth-Fixed system for translation CoM-&gt;APC</li>
 <li>Differential Code Bias P1C1 [m]</li>
@@ -309,5 +309,5 @@
 
 <p>
-When using clocks from Broadcast Ephemeris (with or without applied corrections) or clocks from SP3 files, it may be important to understand that they are not corrected for the 2nd-order relativistic effect. The 2nd-order relativistic effect is a priodic time correction defined as -2 (R * V) / c^2 and includes the scalar product of satallite position and velocity divided by the speed of light raised to the second power. 
+When using clocks from Broadcast Ephemeris (with or without applied corrections) or clocks from SP3 files, it may be important to understand that they are not corrected for the conventional periodic relativistic effect. Chapter 10 of the IERS Conventions 2003 mentions that the conventional periodic relativistic correction to the satellite clock (to be added to the broadcast clock) is computed as dt =  -2 (R * V) / c^2 where R *V is the scalar product of the satellite position and velocity and c is the speed of light. This can also be found in the GPS Interface Specification, IS-GPS-200, Revision D, 7 March 2006.
 </p>
 
@@ -537,5 +537,5 @@
 
 </p>
-Note that clocks in the Clock RINEX files are not corrected for the 2nd-order relativistic effect.
+Note that clocks in the Clock RINEX files are not corrected for the conventional periodic relativistic effect.
 </p>
 
@@ -559,5 +559,5 @@
 </p>
 </p>
-Note that clocks in the SP3 Orbit files are not corrected for the 2nd-order relativistic effect.
+Note that clocks in the SP3 Orbit files are not corrected for the conventional periodic relativistic effect.
 </p>