A historic district is a collection of historic resources that are linked geographically or thematically.
The City of Philadelphia’s historic preservation ordinance, Section 14-1000 of the Philadelphia Code, authorizes the Philadelphia Historical Commission to designate buildings, structures, sites, objects, and districts as historic.
The National Register of Historic Places and landmarks is the federal government’s official list of the nation's historic places worthy of preservation.
The Philadelphia Register of Historic Places is the comprehensive, dynamic inventory of buildings, structures, sites, objects, interiors, and districts that the Philadelphia Historical Commission has designated as historic
The Historical Commission authorizes property owners to install specially-made cast metal plaques on historically-designated buildings, structures, sites, objects, and interiors that are in restored condition.