What is Dutch-processed cocoa?
Dutch-processed cocoa is cocoa powder treated with an alkalising agent to cut acidity and darken it, and it goes into baking far more often than into a bar.
A chocolate bar is made from cocoa mass and cocoa butter. Cocoa powder is what remains once the butter has been pressed out of the mass, and alkalising is done to the nibs, the liquor or that pressed powder. Almost everything that comes out of it is sold as powder for baking and drinks.
It reaches a bar in two ways. A maker adds alkalised powder back for colour and an even, low-acid taste, which is common in industrial and flavoured bars, or the liquor itself was alkalised before the bar was made. A US label calls either "processed with alkali". A European label lists the agent instead, usually as an acidity regulator such as potassium or sodium carbonate.
Fewer than one bar in two hundred on Chof is marked alkalised. The mark is set when the ingredient list says so, and the Chof Score counts it against the bar under Process. A bar with no mark has an ingredient list that does not mention it, which is all Chof knows about it.