With sensible indentation, and knowing nothing of SVG, the only unreadable part of that is the blob of matrix data, but I'm very glad they didn't go with something like <matrixElement row="0" column="0">0.90</matrixElement><matrixElement row="0" col="1">0</matrixElement>...

I just looked, and apparently the matrix values can contain arbitrary whitespace including newlines, so even that's not a very strong criticism. https://developer.mozilla.org/en-US/docs/Web/SVG/Element/feC...