Index: /trunk/BNC/src/bncwindow.cpp
===================================================================
--- /trunk/BNC/src/bncwindow.cpp	(revision 6695)
+++ /trunk/BNC/src/bncwindow.cpp	(revision 6696)
@@ -1246,5 +1246,5 @@
   _miscPortLineEdit->setWhatsThis(tr("BNC can output an incoming stream through a TCP/IP port of your local host. Specify a port number here to activate this function."));
   _scanRTCMCheckBox->setWhatsThis(tr("<p>Tick 'Scan RTCM' to log the numbers of incomming message types as well as contained antenna coordinates, antenna heigt, and antenna descriptor.</p><p>In case of RTCM Version 3 MSM streams, BNC will also log contained RINEX Version 3 observation types.</p>."));
-  _serialMountPointLineEdit->setWhatsThis(tr("<p>Enter a 'Mountpoint' to forward the corresponding stream to a serial connected receiver.</p>"));
+  _serialMountPointLineEdit->setWhatsThis(tr("<p>Enter a 'Mountpoint' to forward the corresponding stream to a serial connected receiver.</p><p>Depending on the stream contents the receiver may use it for Differential GNSS, Precise Point Positioning or any other purpose supported by the firmware.</p>"));
   _serialPortNameLineEdit->setWhatsThis(tr("<p>Enter the serial 'Port name' selected for communication with your serial connected receiver. Valid port names are</p><pre>Windows:       COM1, COM2<br>Linux:         /dev/ttyS0, /dev/ttyS1<br>FreeBSD:       /dev/ttyd0, /dev/ttyd1<br>Digital Unix:  /dev/tty01, /dev/tty02<br>HP-UX:         /dev/tty1p0, /dev/tty2p0<br>SGI/IRIX:      /dev/ttyf1, /dev/ttyf2<br>SunOS/Solaris: /dev/ttya, /dev/ttyb</pre><p>Note that you must plug a serial cable in the port defined here before you start BNC.</p>"));
   _serialBaudRateComboBox->setWhatsThis(tr("<p>Select a 'Baud rate' for the serial output link.</p><p>Note that your selection must equal the baud rate configured to the serial connected receiver. Note further that using a high baud rate is recommended.</p>"));
@@ -1253,5 +1253,5 @@
   _serialStopBitsComboBox->setWhatsThis(tr("<p>Select the number of 'Stop bits' for the serial output link.</p><p>Note that your selection must equal the number of stop bits configured to the serial connected receiver. Note further that often 1 stop bit is used.</p>"));
   _serialFlowControlComboBox->setWhatsThis(tr("<p>Select a 'Flow control' for the serial output link.</p><p>Note that your selection must equal the flow control configured to the serial connected receiver. Select 'OFF' if you don't know better.</p>"));
-  _serialAutoNMEAComboBox->setWhatsThis(tr("<p>Select 'no' if you don't want BNC to forward or upload any NMEA message to the NTRIP broadcaster following the 'Virtural Reference Station' concept.</p><p>Select 'Auto' to automatically forward NMEA messages of type GPGGA or GNGGA from your serial connected receiver to the NTRIP broadcaster and/or save them in a file.</p><p>Select 'Manual' if you want BNC to produce and upload one initial GPGGA NMEA message to the NTRIP broadcaster because your serial connected receiver doesn't generate these messages.</p>"));
+  _serialAutoNMEAComboBox->setWhatsThis(tr("<p>The 'NMEA' option supports the so-called 'Virtural Reference Station' (VRS) concept which requires the receiver to send approximate position information to the NTRIP Broadcaster. Select 'no' if you don't want BNC to forward or upload any NMEA message to the NTRIP broadcaster in support of VRS.</p><p>Select 'Auto' to automatically forward NMEA messages of type GPGGA or GNGGA from your serial connected receiver to the NTRIP broadcaster and/or save them in a file.</p><p>Select 'Manual' if you want BNC to produce and upload one initial GPGGA NMEA message to the NTRIP broadcaster because your serial connected receiver doesn't generate these messages.</p>"));
   _serialFileNMEALineEdit->setWhatsThis(tr("<p>Specify the full path to a file where NMEA messages coming from your serial connected receiver are saved.</p>"));
   _serialHeightNMEALineEdit->setWhatsThis(tr("<p>Specify an approximate 'Height' above mean sea level in meters for the reference station introduced through 'Mountpoint'. Together with the latitude and longitude from the NTRIP broadcaster sourcetable the height information is used to build one initial GPGGA message to be sent to the NTRIP broadcaster.</p><p>This option is only relevant when option 'NMEA' is set to 'Manual'.</p>"));