| 359 / | HD | OPTICS: SYSTEMS (INCLUDING COMMUNICATION) AND ELEMENTS |
| 838 | DF | MIRROR {14} |
| 850 | DF | .~ Plural mirrors or reflecting surfaces {7} |
| 857 | DF | .~.~ With successive reflections {4} |
| 862 | ![]() | .~.~.~ Including an adjustable mirror {1} |
| 863 | DF | .~.~.~.~> Including a curved mirror |