+RRDtool comes with a preset default font. You can set the environment
+variable C<RRD_DEFAULT_FONT> if you want to change this.
+
+Truetype fonts are only supported for PNG output. See below.
+
+[B<-R>|B<--font-render-mode> {I<normal>,I<light>,I<mono>}]
+
+This lets you customize the strength of the font smoothing,
+or disable it entirely using I<mono>. By default, I<normal>
+font smoothing is used.
+
+[B<-B>|B<--font-smoothing-threshold> I<size>]
+
+This specifies the largest font size which will be rendered
+bitmapped, that is, without any font smoothing. By default,
+no text is rendered bitmapped.
+
+[B<-E>|B<--slope-mode>]
+
+RRDtool graphs are composed of stair case curves by default. This is in line with
+the way RRDtool calculates its data. Some people favor a more 'organic' look
+for their graphs even though it is not all that true.
+
+[B<-a>|B<--imgformat> B<PNG>|B<SVG>|B<EPS>|B<PDF>]
+
+Image format for the generated graph. For the vector formats you can
+choose among the standard Postscript fonts Courier-Bold,
+Courier-BoldOblique, Courier-Oblique, Courier, Helvetica-Bold,
+Helvetica-BoldOblique, Helvetica-Oblique, Helvetica, Symbol,
+Times-Bold, Times-BoldItalic, Times-Italic, Times-Roman, and ZapfDingbats.
+
+[B<-i>|B<--interlaced>]
+
+If images are interlaced they become visible on browsers more quickly.
+
+[B<-g>|B<--no-legend>]
+
+Suppress generation of the legend; only render the graph.
+
+[B<-F>|B<--force-rules-legend>]
+
+Force the generation of HRULE and VRULE legends even if those HRULE or
+VRULE will not be drawn because out of graph boundaries (mimics
+behaviour of pre 1.0.42 versions).
+
+[B<-T>|B<--tabwidth> I<value>]
+
+By default the tab-width is 40 pixels, use this option to change it.
+
+[B<-b>|B<--base> I<value>]