+This option is very effective at confusing the heck out of the default
+rrdtool autoscaler and grid painter. If rrdtool detects that it is not
+successful in labeling the graph under the given circumstances, it will switch
+to the more robust B<--alt-y-grid> mode.
+
+B<[-L|--units-length E<lt>valueE<gt>]>
+
+How many digits should rrdtool assume the y-axis labels to be ? You may have to use this option
+to make enough space once you start fideling with the y-axis labeling.
+