Compile time improvments for NetWare and Win32 -- Guenter Knauf gk.gknw.de

[rrdtool-all.git] / program / doc / rrdgraph_data.pod

diff --git a/program/doc/rrdgraph_data.pod b/program/doc/rrdgraph_data.pod
index e8b2c6719d3ecebb658bc0bd72c059b9745d2f7d..04d976174b4a679cf0eac31a2589d99f6d3e3e6e 100644 (file)
--- a/program/doc/rrdgraph_data.pod
+++ b/program/doc/rrdgraph_data.pod
@@ -19,6 +19,9 @@ useful information such as maximum, minimum etcetera. Two of the
 instructions use a language called B<RPN> which is described in its
 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.
+
 =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>>]
@@ -68,6 +71,9 @@ elements.
 
 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>