Index: /trunk/BNC/src/bnchelp.html
===================================================================
--- /trunk/BNC/src/bnchelp.html (revision 6629)
+++ /trunk/BNC/src/bnchelp.html (revision 6630)
@@ -700,5 +700,5 @@
Signals with attribute 'C' enjoy the highest priority. If such a Version 3 observation becomes available it is presented as RINEX Version 2 observation if that is the format you wish to see. Observations with other attributes are ignored.
If no signal with 'C' attribute is available but we have an observation with 'W' attribute, BNC presents that one as RINEX Version 2 observation and ignores all observations with other attributes. The same applies mutatis mutandis to observations with P and X attributes.
-If no signal with 'C', 'W', 'P', or 'X' attribute is availalbe but a signal with undefined generation attribute (blank character, '_') exists, BNC presents that one as RINEX Version 2 observation.
+If no signal with 'C', 'W', 'P', or 'X' attribute is availalbe but a signal with undefined generation attribute (underscore character, '_') exists, BNC presents that one as RINEX Version 2 observation.
If no signal with 'C', 'W', 'P', 'X', or '_' generation attribute exists then the question mark '?' tells BNC to present the first of any other appearing signal as RINEX Version 2 observation.