own manual page.
Variable names (I<vname>) must be made up strings of the following characters
-C<A-Z, a-z, 0-9, -,_>, starting with a letter and a maximum length of 255 characters.
+C<A-Z, a-z, 0-9, -,_> and a maximum length of 255 characters.
+
+When picking variable names, make sure you do not choose a name that is
+already taken by an RPN operator. A save bet it to use lowercase or
+mixedcase names for variables since operators will always be in uppercase.
=head1 DEF
Example: C<VDEF:avg=mydata,AVERAGE>
+Note that currently only agregation functions work in VDEF rpn expressions.
+Patches to change this are welcome.
+
=head1 CDEF
B<CDEF>:I<vname>=I<RPN expression>
=head1 AUTHOR
-Program by Tobias Oetiker E<lt>oetiker@ee.ethz.chE<gt>
+Program by Tobias Oetiker E<lt>tobi@oetiker.chE<gt>
This manual page by Alex van den Bogaerdt E<lt>alex@ergens.op.het.netE<gt>