Structured documents generally focus on labeling things that can be used for a variety of processing purposes, not merely formatting. For example, explicit labeling of "chapter title" or "emphasis" is far more useful to systems for the visually impaired, than merely "Helvetica bold 24" or "italic". In the same way, meaningful labeling of the many items on a technical information sheet enables far better integration with databases, search systems, online catalogs, and so on.

Structured documents generally support at least hierarchical