--- doc/docbase/instrument_scripts/nksp/01_nksp.html	2017/04/21 16:02:47	3119
+++ doc/docbase/instrument_scripts/nksp/01_nksp.html	2017/05/19 15:19:37	3191
@@ -254,7 +254,8 @@
     <p>
       The left hand side's <code>??variable-name??</code> is an arbitrary name
       you can chose for your variable. That name might consist of English
-      letters A to Z (lower and upper case) and the underscore character "<code>_</code>".
+      letters A to Z (lower and upper case), digits (<code>0</code> to <code>9</code>),
+      and the underscore character "<code>_</code>".
       Variable names must be unique. So you can neither declare several variables
       with the same name, nor can you use a name for your variable that is
       already been reserved by <i>built-in variables</i>.