# Tag Info

## About output-routine

{output-routine} is a basic element of TeX processing which is automatically called at different occasions (e.g., at insertions like footnotes or floats) and finally makes up the contents of a page for shipout after a page break has occurred. Headers and footers as well as floats, margin paragraphs and footnotes are added here.

The output routine is a basic element of TeX processing which is automatically called at different occasions (e.g., at insertions like footnotes or floats) and finally makes up the contents of a page for shipout after a page break has occurred. Headers and footers as well as floats, margin paragraphs and footnotes are added here.

Technically, `\output` is a token register which is executed automatically at every page break. It gets the contents of the main vertical list (that is, the type area) in box `\@cclv` (that is, 255) and adds all the stuff which goes outside of it on the page (plus floats which are inserted) before calling `\shipout` for really producing a page in the `dvi` or `pdf` file.

The output routine is defined by the basic format used (for instance, plain TeX, LaTeX or ConTeXt) and has a large influence on the "flavour" of this format and its page building capabilities. Only very few packages manipulate the output routine (like `longtable` or `multicol`), and this has to be done with great care to avoid conflicts.

Questions with this tag are concerned with basic considerations of page building, page breaking, headers, floating items (including `\marginpar`) or footnotes.