CKey Format v0.20.0 — Profile 3 Filled Polar Field

Profile 3 retains the 116-unit field, ten byte-interleaved RS(255,k) blocks, seven capacity/ECC tiers, deterministic visual fill, 232×232 Cartesian pitch, and 576 calibrated Gray-length/stroke-weight rays.

Its ring matrix now uses 34 concentric rings at radii 3.50 + 0.62r, for r = 0…33. The innermost usable ring is close to the centre and the outermost is 23.96, leaving a measurable gap before the Ring Key at radius 24.45 and the Ray Key at radius 26.30. Dots remain radius 0.075; capacity comes from filling unused radial space, not shrinking dots.

Cartesian payload sites reserve a 5-unit border moat. This prevents data from spilling into the 2.6-unit rounded frame under anti-aliasing, display blur, or camera blur. The Grid Key remains four ordinary .34 marks on .5 pitch.

Encoders emit frame format byte 0x14 (decimal 20), profile byte 0x03. This changes the codeword-to-site mapping and requires the v0.20 sampling map.