This tag refers to the LaTeX \pagestyle command, which is used to format running heads and footers.

The \pagestyle command provides a mechanism for defining the content and appearance of running heads and footers, including text and page numbers. Multiple styles may be defined, to be used as appropriate on different pages. Common styles are plain (no header, page number centered in the footer, commonly used on the first page of a chapter or article) and empty (no header or footer, usually used on otherwise blank pages).