In particular https://drafts.fxtf.org/compositing-1/#canvascompositingandblending cannot define the values in terms of CSS values. See also https://www.w3.org/Bugs/Public/show_bug.cgi?id=27313.

What would be good I think is to have a table that links the string value (used for canvas), CSS value (used for CSS), and algorithm together.

(It would also be somewhat nice if the algorithm sections list the value used for them and not just a title cased header.)