Index: trunk/BNC/bnchelp.html
===================================================================
--- trunk/BNC/bnchelp.html	(revision 263)
+++ trunk/BNC/bnchelp.html	(revision 264)
@@ -127,5 +127,5 @@
 </p>
 <p>
-In case an observable is unavailable, its value is set to zero '0.000'.
+In case an observation is unavailable, its value is set to zero '0.000'.
 </p>
 <a name="wait">