Reference Maps include a variety of map types that show the boundaries and names of geographic areas for which the Census Bureau tabulates statistical data. In some cases, the name is only in the form of a geographic code, such as a census block number. Some types of reference maps include geographic features and their identifiers that are coincident with the boundary. Examples are roads and water features. Reference maps can include additional features such as railroads to aid users in orienting themselves to the area depicted on the map.