Visual-Meta is a method of including metadata visibly in a document, in a human and machine readable Appendix, on the same visual level as the content, rather than hidden in the datafile, making ordinary text richly interactive.

Instead of trying to invent a new document format substrate to unleash the potential of richly interactive digital text, this approach takes ‘normal’ PDF text and makes it interactive. It is currently possible to embed some metadata in PDF but it is rarely done and does not include structural information. Visual-Meta is very low cost in terms of user investment and technical implementation, since most of the metadata is simply taken from the source document, it is optional what to add manually beyond the author’s name(s) and document title for citation information.

Let’s first look at how metadata is ‘imprinted’ in a paper book:

Traditional Book Approach, the Colophon

A traditional book features a page inside the book, before the main text, with ‘meta’ data ‘about’ the book, including the name of the author, title of the book and imprint information and so on. This page is known as the printer’s imprint in the UK, where it is mandated by law, and the impressum in Germany, where it is also included by law. Other terms for this page are edition notice or copyright page. Before printing it was at the end of the document as a ‘colophon’, a term which is sometimes also used. 

Copyright © 2010 Alberto Manguel.
All rights reserved.
Designed by Sonia Shannon Set in Fournier type by Tseng Information Systems, Inc.
Printed in the United States of America. Library of Congress Cataloging-Manguel, Alberto. A reader on reading / Alberto Manguel. p. cm. Includes bibliographical references and index.
ISBN 978-0-300-15982-0 (alk. paper) 1. Books and reading. 2. Manguel, Alberto— Books and reading. I. Title. z1003.M2925 2010 028’.9—dc22 2009043719 A catalogue record for this book is available from the British Library.  

The Visual-Meta Approach

Visual-Meta puts this metadata into an Appendix at the back of the document instead of at the front (to make it less obtrusive), written out as visible plain text. It contains citation metadata and can also contain addressing, interaction and formatting information. The PDF viewer can then use this to make the normal PDF text in the document interactive:

author = {Hegland, Frode},
title = {Visual-Meta: An Approach to Surfacing Metadata},
booktitle = {Proceedings of the 2Nd International Workshop on Human Factors in Hypertext}, series = {HUMAN ’19},
year = {2019},
isbn = {978-1-4503-6899-5},
location = {Hof, Germany},
pages = {31–33},
numpages = {3},
url = {},
doi = {10.1145/3345509.3349281},
acmid = {3349281},
publisher = {ACM},
address = {New York, NY, USA},
keywords = {archiving, bibtex citing, citations, engelbart, future, glossary, hypertext, meta,
metadata, ohs, pdf, rfc, text}, }


The benefit is that the PDF viewer software ‘knows’ the citation information of this document so that a reader can cite with a simply copy and paste and change the view of the text since the reader software is aware of the document’s structure and since this metadata is visible at the same level as the content of the document, it will not be stripped out as document formats change and it will not interfere with viewers which are not Visual-Meta aware.

There are further Immediate User Benefits, different User Community Benefits and Visual VS. Embedded Benefits.

Visual-Meta Unleashes Hypertextuality and advanced interactions such as Augmented Copying (copies with full citation information), References and Glossaries, as well as included information for how to parse tables, images and special interactions for graphs. This enables dynamic re-creations of interactions with sophisticated visualisations, which no longer needs to be flattened when committed to PDF.


The Visual-Meta approach is compatible with the Dublin Core Metadata Element Set through simple translations.

Visual-Meta is Extensible for Computational Text, Rights Management and Provenance. Visual-Meta is Not A New Standard (it is BibTeX in a novel use, supported by JSON when that is useful), it builds seamlessly on the legacy PDF format by simply adding plain text metadata in an appendix, and basic Visual-Meta Is Quick & Easy To Add To Legacy Documents.

As more Visual-Meta is used, the openness and connectedness will increase, paving the way towards 5 star open data.


This method of storing metadata is robust since as long as the content of the document is available, the metadata will also be available, even to the point of printing the document, then scanning it and performing OCR on it.

Furthermore, the actual Visual-Meta contains instructions for how to implement it, in plain English language, which will allow any developer to integrate Visual-Meta import or export, now, and in hundreds or thousands of years in the future. Full Visual-Meta Example Including Intro Text


Visual-Meta has been implemented in the Augmented Text suite of software: as well as in The Future of Text book, where the Visual-Meta was added by hand:

Metadata Catered For

Despite the name ‘Visual-Meta’, the solution proposed here is only partly about adding metadata, such as administrative metadata, to the document, the rest is to retain inherent descriptive and structural metadata automatically from the authoring document format (fx. Word’s .doc and Author’s .liquid) to the reading document format (PDF).

The retained inherent data includes the structural description of the document, such as what headings are used.
This is in order to retain the interactions the author had available for interacting with the main text (folding into Table of Contents etc.) and interacting with paratexts (Glossaries, Endnotes and References).
Since data is inherently in the document while it is being authored we refer to it as ‘retained-metadata’.
The only user-added metadata expected in Visual-meta is the descriptive metadata of the author’s name and the title of the document in the Export Dialog–everything else is appended automatically. This is important to make clear since the overhead of adding traditional metadata can be high!

Administrative metadata, semantic markup metadata and any other metadata can of course also be accommodated.

Presentation at the 2020 Summit of the Book

ACM Hypertext 2019 Visual-Meta Presentation

Future Text Initiative

The Visual-Meta approach is part of the Future Text Initiative which also includes the book The Future of Text and the Author, Reader and Liquid software projects.

Further Information


Further description is on the blog: and at: Visual-Meta Example & Structure. Full source code for how we are parsing visual-meta will be made available on request. Addressing is discussed at

The Visual-Meta approach is very much inspired by Doug Engelbart’s notion of an xFile and his insistence that high-resolution addressability should be human readable. Here is an brief chat with Doug from the early 2010s, with more available on

Frode Hegland
London 2021

To get involved, please feel free to contact the developer of Visual-Meta Frode Hegland :