Architectural letters and logos are individual, stand-alone elements attached to the elevation of a building. Strictly speaking they would not have a background (other than the building itself) or panel but we have included all 3D (three dimensional) lettering in this category.

They are so called because they add to the architectural characteristics of the building as opposed to panel signs that tend to disfigure or obliterate parts of the building if sized or sighted insensitively.