Cross-Reference
A pointer inside a document to another passage of the same document, using consistent language such as 'see above' or 'infra'.
A cross-reference is an internal citation: rather than pointing to an outside source, it points to another passage of the same work. Legal writers use 'supra' and 'infra'; academic writers use 'see above', 'see below', 'as noted in §3.2'; book editors use running heads, chapter numbers, and index entries. All accomplish the same navigation: they save the reader from re-encountering an argument the writer has already made.
Well-made cross-references stabilise long documents. A hundred-page report can only work as an argument if the reader can follow how §7 depends on §3; a novel with many characters becomes readable when the editorial apparatus (chapter numbers, a dramatis personae) makes it possible to check who is who without losing the thread.
The discipline is maintenance. Cross-references break when a section is renumbered, when a paragraph is moved, when a page reference in a hardcover proof no longer matches the paperback pagination. Publishing workflows encode this by using named anchors (section labels rather than page numbers) that survive layout changes and only resolve to concrete pointers at typesetting.
Common mistake: cross-referencing forward to material the reader has not yet read, and expecting the reader to accept a claim on the strength of it. Forward references should be sparing: they promise a payoff and, when the payoff comes, the reader has to be able to remember why it was promised.
“The doctrine's origins are discussed in §2.1, and its modern application is treated at length in §7 (infra).”
Keep reading the glossary
A cross-reference meaning 'above' — used to point back to a source or passage cited earlier in the same document.
A cross-reference meaning 'below' — used to point forward to a source or passage discussed later in the same document.
A citation shorthand that assigns a short form to a long source name for later reference within the same document.
A short-form citation meaning 'the same source as the one immediately preceding' — the legal cousin of 'ibid.'