The czako is a peakless cardboard cylinder 12.5 cm high, covered in matte black crepe, carrying a gilt hammer-and-chisel on the front and a bundle of stiff cockerel hackles mounted off its left side. That plume began as the brush a miner tucked into his hat band to sweep out blast holes; it now carries rank.

Green is a director general, white is operations supervision, black is a rank-and-file miner, red is the band, red-and-white its bandmaster. Read across a Barbórka procession, the colour tells you the office before the face does. This system treats colour the same way — as an assignment, never as a mood.