Crop (c)
c:{x}:{y}:{width}:{height} crops the source to a rectangle given in
normalized coordinates (0–1, relative to the source dimensions), then
the rest of the ops chain applies to the cropped result. Normalized rects
are resolution-independent: the same URL is correct whatever rendition size
the pipeline picks.
Coordinates are written with exactly six decimals — one rectangle, one
URL, one cache entry. The rect must stay inside the source
(x + width ≤ 1, y + height ≤ 1) and have non-zero area.
w:400.webp — the source, untouched https://img.brandcenter.io/i/barre3/cG4wbk45c3lZNTZyMGxOM2RYV0M2TDV2SU1kT2JiVzU/1/w:400.webp 
c:0.280000:0.020000:0.440000:0.560000,w:400.webp — cropped to the coach — same URL grammar at any rendition size https://img.brandcenter.io/i/barre3/cG4wbk45c3lZNTZyMGxOM2RYV0M2TDV2SU1kT2JiVzU/1/c:0.280000:0.020000:0.440000:0.560000,w:400.webp 
c:0.250000:0.250000:0.500000:0.500000,w:128.webp — the center quarter of the hero, then fit inside 128 https://img.brandcenter.io/i/bc/aHVFd2tZTjRGZW5lTlh5T09RVHJmRXNFZUVobjEzdkQ/1/c:0.250000:0.250000:0.500000:0.500000,w:128.webp Ephemeral vs durable
Section titled “Ephemeral vs durable”Unsigned crop URLs render immediately and cache at the CDN, and keep rendering forever — this is the tier CMS plugin embeds use. They are not persisted at the origin, so a cache eviction means a re-render (cheap, transparent). For URLs whose renders should be pinned durably — never re-rendered, immune to cache eviction — a backend can sign them: validly signed renders persist.