Another vent pipe question

Been checking install instructions to help with stove purchase. Install instructions state venting clearance to a window or door that opens must be 48" to side, 48" below,12" above( with outside air installed, 18" to the side or below). So does this mean if I install outside air I can have the vent 18" from opening door or window? Building code office said they go by whatever the install manual says. Thanks