halacha - Making a Berachah on rabbinically prohibited foods

Should one refrain from making a Berachah on rabbinically prohibited foods, or does that rule only apply to biblically prohibited foods?

Answer

אכל דבר איסור, אף על פי שאינו אסור אלא מדרבנן, אין מזמנין עליו ואין מברכין עליו לא בתחלה ולא בסוף. (שולחן ערוך או"ח סימן קצו:א)‏
If one ate something prohibited, even if it was only prohibited rabbinically, one does not combine him to a zimmun, nor would he say a beginning or after blessing [on that food]. (Shulchan Aruch OC 196:1)