A dust jacket is a loose detatchable outer cover for your hardback book and is optional. It is printed one side on lightweight paper. You can choose from a silk or gloss coated paper. Please remember that this is not the same paper you buy for your inkjet at home. Gloss does not mean a very high gloss level, it has a gloss sheen. Silk is a matt finish with a slight sheen. You can ask the helpdesk for samples if you are not sure whether this is what you want. Laminating is not currently available on this product, but is technically possible for larger quantities.
The "line-block" directive constructs an element where line breaks and initial indentation is significant and inline markup is supported. It is equivalent to a parsed literal block with different rendering: typically in an ordinary serif typeface instead of a typewriter/monospaced face, and not automatically indented. (Have the line-block directive begin a block quote to get an indented line block.) Line blocks are useful for address blocks and verse (poetry, song lyrics), where the structure of lines is significant. For example, here's a classic: