X-Git-Url: https://git.octo.it/?p=rrdtool.git;a=blobdiff_plain;f=doc%2Frrdgraph_data.pod;h=c26868f0e509ffe00559f52922ae16a770d9daf2;hp=04d976174b4a679cf0eac31a2589d99f6d3e3e6e;hb=22129bb15a8ad204cf8a5e88e8834ec0b51908c0;hpb=81ed9c86d4042e31e147b53bf14da233b6524021

diff --git a/doc/rrdgraph_data.pod b/doc/rrdgraph_data.pod
index 04d9761..c26868f 100644
--- a/doc/rrdgraph_data.pod
+++ b/doc/rrdgraph_data.pod
@@ -22,6 +22,10 @@ own manual page.
 Variable names (I<vname>) must be made up strings of the following 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 safe bet it to use lowercase or
+mixedcase names for variables since operators will always be in uppercase.
+
 =head1 DEF
 
 B<DEF:>I<E<lt>vnameE<gt>>=I<E<lt>rrdfileE<gt>>:I<E<lt>ds-nameE<gt>>:I<E<lt>CFE<gt>>[:step=I<E<lt>stepE<gt>>][:start=I<E<lt>timeE<gt>>][:end=I<E<lt>timeE<gt>>][:reduce=I<E<lt>B<CF>E<gt>>]
@@ -97,6 +101,6 @@ Make sure to read L<rrdgraph_examples> for tipsE<amp>tricks.
 
 =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>