Since PDF 1.5 portions of a page can be marked for better accessibility support. For example, replacement texts or expansions of abbreviations can be provided. This package starts with providing a minimal low-level interface for programmers; its status is experimental. Support necessary for the package was added to the "distill" capabilities of Ghostscript with version 9.15 of Ghostscript; the dvips is only available with that version (or later).