---
title: "Cross-reference (xref)"
source: https://dev.pageseeder.com/reference/glossary/cross_reference.html
description: "Cross-references (xrefs) are fundamental PageSeeder components used to assemble documents and fragments into publications or create associations between content. Unlike conventional links, they are rich, customizable structures represented by `<xref>` and `<blockxref>` elements that can represent semantics like footnotes and citations."
last_updated: 2026-09-08T11:47:40+10:00
tokens: ~272
---

# Cross-reference (xref)

Also known as an **xref**. 

These are a fundamental components of the PageSeeder architecture and can be used in multiple ways, including the following:

- Assembling components ([documents](document.md) or [fragments](fragment.md)) into a [publication](publications.md).
- Creating associations between [document](document.md) content.

Unlike links in conventional publishing applications or HTML, PageSeeder cross-references are rich structures that developers can customize or override. In PSML, cross-references are represented by the following elements:

- `<xref>`
- `<blockxref>`

Using [labels](cross_reference_label.md) or the [xref config](../../guide/configuration/psml/psml_xref_config.md) allows semantics to be attached to xrefs. This makes it possible to represent [objects](object_labels.md) such as footnotes, end notes, citations and many other structures.

## Terminology

> **Note:** The source document refers to the document containing the original cross-reference in its content. The target document refers to document being pointed at.