X-Git-Url: https://git.octo.it/?a=blobdiff_plain;f=doc%2Frrdgraph_data.pod;h=dba53f3720a4a302b2cc8651545eed3a993bbd89;hb=9b8a8e557d4c271ad4efe95c4b7bb7f0803e729c;hp=5b71c87f94b924c452fb3416a5cd5050cebcfaeb;hpb=26f7c5c1ba83c8ab82cd271b143061f7fb13394c;p=rrdtool.git

diff --git a/doc/rrdgraph_data.pod b/doc/rrdgraph_data.pod
index 5b71c87..dba53f3 100644
--- a/doc/rrdgraph_data.pod
+++ b/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, -,_>, starting with a letter 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>>]
@@ -27,7 +30,7 @@ This command fetches data from an B<RRD> file.  The virtual name
 I<vname> can then be used throughout the rest of the script. By
 default, an B<RRA> which contains the correct consolidated data
 at an appropriate resolution will be chosen.  The resolution can
-be overridden with the L<--step|rrdgraph/item_Time> option. 
+be overridden with the L<--step|rrdgraph/item_Time> option.
 The resolution can again be overridden by specifying the B<step size>.
 The time span of this data is the same as for the graph by default,
 you can override this by specifying B<start and end>.  Remember to