Pittsburgh History and Landmarks Foundation (PHLF) Historic Landmark plaque program was begun in 1968 in order to identify architecturally significant structures as well as significant pieces of Pittsburgh's local heritage throughout Allegheny County. Nominations are reviewed by the private non-profit foundation's Historic Plaque Designation Committee composed of trustees, architectural historians, and citizens. These designations are not to be confused with City of Pittsburgh historic designations. Beginning in 2010, the committee expanded its program to consider applications for historic status from counties surrounding Allegheny, extending its reach to a 250-mile radius from the city, as long as the site has a connection to the greater Pittsburgh region. Historic designation by the foundation does not protect the building from alteration or demolition. Structures awarded the designation typically have aluminum or bronze plaques affixed to their exterior that signify their status.