Subdivided land in urban areas is often described merely by reference to a surveyor's plat or map that describes the parcels in an area together with streets and public areas. Lots in such maps or plats are numbered, and the deed to a particular numbered lot that incorporates by reference a map or plat containing a legal description of the boundaries of such numbered lot is a sufficient description of the property. Although such plats are usually recorded, an unrecorded plat is sufficient to describe property so long as it is clearly incorporated in the deed, and a copy of the plat can be found.
The parcel number is the primary identification for a specific piece of real estate property in a particular county. The county recorder's office typically can locate the plat for a particular piece of property through looking up information about the parcel number in order to locate the book and page number of the book that contains that plat.