| 52 / | HD | STATIC STRUCTURES (E.G., BUILDINGS) |
| 506.01 | DF | SHEETLIKE ELEMENT ASSEMBLED PARALLEL TO EXISTING WALL, CEILING, OR FLOOR (E.G., INSULATING PANEL, SHEATHING) {10} |
| 506.06 | DF | .~ Element spaced from wall, ceiling, or floor and held by discrete retaining means (e.g., suspended ceiling or wall) {2} |
| 506.08 | DF | .~.~ Section designed (e.g., groove, integral hanger) to fasten to retaining means {1} |
| 506.09 | | .~.~.~ Having abutting edges to conceal retaining means {1} |
| 506.1 | DF | .~.~.~.~> Edges interfit |