HABS/HAER/HALS records include both formal documentation (drawings, photographs, histories) and informal documentation (field records, and other significant materials not meeting HABS/HAER/HALS standards):

• Measured drawings are produced at a precise scale from actual dimensions recorded in the field. Drawings may be produced either by hand or with computer-aided drafting (CAD).

• Large-format photographs are produced as contact prints from 4x5 and 5x7 black-and-white negatives and color transparencies. The formats allow maximum enlargement with minimal loss of detail and clarity, and the black-and-white processing allows for achival stability.

• Written histories place the site or structure within the appropriate context, addressing both the historical and the architectural or engineering aspects of its significance.

• Field records are not considered formal documentation because they are the notes, sketches and 35 mm photographs used to create the drawings. Nevertheless, they are the primary source of HABS/HAER/HALS measured drawings and can reveal aspects of a structure or site not emphasized in the formal documentation. They are an important record of the documentation process, and often provide the greatest detail. In addition, field records sometimes include copies of historical views or documents.