| 535-1/-9 | Special auxiliary subdivision for optics |
| 535.1 | Theory of light |
| 535.2 | Propagation and energetics of radiation. Photometry |
| 535.3 | Propagation. Reflection. Refraction. Absorption. Emission |
| 535.4 | Interference. Diffraction. Scattering by diffraction |
| 535.5 | Polarization. Double refraction. Dispersion in anisotropic bodies |
| 535.6 | Colours and their properties. Colour theory |
| 535.8 | Applications of optics in general |
