Hi Julie. There are often fields in the MLS to designate what kind of bathroom is on the property. A full bath has a toilet, sink, shower and tub. A 3/4 bath is minus the tub and a half bath, also called a powder room, is the toilet and sink. If the bathroom is on the premises, but not listed on the assessor's records, then it's ok to show it on the MLS. Does this make sense to you?