[DOC] Mention XML configuration can override internal defaults.

diff --git a/help/C/viking.xml b/help/C/viking.xml
index c08c4a072b2aa9d9a05d96a5991396bc0fbb97bd..57b1f7f53eadba9d15e55ee952cd7159bf52dc2c 100644 (file)
--- a/help/C/viking.xml
+++ b/help/C/viking.xml
@@ -3062,6 +3062,11 @@ Accept: */*
 </programlisting>
 </para>
       <para>You can find more examples in the documentation part of the distribution.</para>
+      <para>
+       It is also possible to override the internal defaults e.g. to update any parameters should they change over time,
+       by adding the values into your configuration file.
+       When you define object group that already exists (and for Maps this means by a repeated Id key, but you may have to examine the source code to work out what the relevant Id values are) then you need to define all the other keys as well, otherwise they will be reset to the defaults.
+      </para>
       <section id="map_source" xreflabel="Map Source Extensions">
         <title>Map Source</title>
         <para>It is possible to add new map's sources. The file is <filename>~/.viking/maps.xml</filename> for <trademark>UNIX</trademark> like systems, <filename>C:\Documents and Settings\<replaceable>username</replaceable>\.viking\maps.xml</filename> on <trademark>Windows XP</trademark> or <filename>C:\Users\<replaceable>username</replaceable>\.viking\maps.xml</filename> on <trademark>Windows 7</trademark> onwards.</para>