HRULE (Deprecated)

Hi all,

I'm graphing a cisco 6500 switch which has 48 fast ethernet ports.

I would like to put a red horizontal line in that port that has the QoS
enables.

For example, if I have a port used whit virtual limit at 2 mb I never
see that red line cos the port is 100 mb.
This is my rrd graph

rrdtool graph - -h 250 -w 750 -v Bits/s --rigid \
DEF:A=$name:in:AVERAGE \
DEF:B=$name:out:AVERAGE \
CDEF:C=A,8,* \
CDEF:D=B,8,* \
COMMENT:'\\n' \
COMMENT:' maximum average current\\n' \
AREA:C#00FF00:\"In \" \
GPRINT:C:MAX:'%7.2lf %sb/s' \
GPRINT:C:AVERAGE:'%7.2lf %Sb/s' \
GPRINT:C:LAST:\"%7.2lf %Sb/s\\n\" \
LINE1:D#0000FF:\"Out \" \
GPRINT:D:MAX:'%7.2lf %Sb/s' \
GPRINT:D:AVERAGE:'%7.2lf %Sb/s' \
GPRINT:D:LAST:'%7.2lf %Sb/s\\n'

Can somebody help me?
I'm using the last one rrdtool 1.2