This is a block using "sketch-styling" in HTML Attributes -> Class - so in the whole block all underline and strikethrough are formatted with our custom design.

... underline adasdsad strikethrougn etstdfdf gfsgdfgdsfhfdhhffdhtdfdf gfsgdfgdsfhfdhhffdhtdfdf gfsgdfgdsfhfdhhffdhtdfdf gfsgdfgdsfhfdhhffdhtdfdf gfsgdfgdsfhfdhhffdhtdfdf gfsgdfgdsfhfdhhffdhtdfdf gfsgdfgdsfhfdhhffdhtdfdf gfsgdfgdsfhfdhhffdhtdfdf gfsgdfgdsfhfdhhffdhtdfdf gfsgdfgdsfhfdhhffdhtdfdf gfsgdfgdsfhfdhhffdh