Taken from the FAQ:
Taunt Macro:
From WoWWiki wrote:
#showtooltip
/cast [help][target=targettarget,help] Righteous Defense;
This will put righteous defense on your target if it is friendly, and on your target's target if it is not friendly.
From WoWWiki wrote:
#showtooltip
/cast [target=mouseover,help][help][target=targettarget,help] Righteous Defense;
This does the same as above, and it will also cast RD on the target if your mouse is over that target.