The concept of document navigation tools such as bookmarks and tables of contents have been around for centuries. However, they’re often underused or misused, so I wanted to go back to the basics here, and talk about what these items really are today, and where they are – and are not – appropriate. What is the difference between the two, and is one better than the other?
The Table of Contents
The table of contents is usually one or more pages found towards the beginning of the document and provides a quick understanding of the structure of the document: chapters, sections, subjects, etc., and the page number those items can be found on. Clever use of indentation can elude to the fact that one topic is a part of another, larger subject or a subheading.
The advantage of having a table of contents is that it becomes a part of the content; often the table of contents references itself. This is an advantage because if you were to print a hardcopy of the document, you can retain this navigation tool to quickly look up the topic of interest, determine the page number, and then use your fingers to navigate to that page.
It is by far the best way to navigate between sections of the document, and it also allows you to see where you are in most documents, as your current location will be highlighted. (Notice in the image how the table of contents item is highlighted with a light grey bar? This shows we’re currently on that page.)
The disadvantage of PDF bookmarks is that they’re only available when viewing this content in a PDF viewer that supports it. While most PDF viewers will support the display and navigation of PDF bookmarks, if you were to print the document, or convert it to an alternative format, you lose this navigation tool.
Which navigation tool to go with?
Ultimately it is the delivery vehicle (electronic vs. paper) that will drive which navigation tools to use. It doesn’t make sense to navigate back to the table of contents in a document when you’re already in the middle of it, so a table of contents is not particularly useful if your documents will only be delivered electronically in PDF format. However, if you primarily, or even occasionally, generate hardcopy versions of your documents, the PDF bookmarks are lost, and the table of contents becomes quite important.
Either way PDF, which has become the standard file format for exchanging and archiving documents, provides flexible and convenient options for allowing the consumers of your documents to quickly navigate to the content they are looking for. Rendering platforms, such as Adlib, can intelligently generate these navigation tools for you by automatically analyzing the structure of your documents and incorporating that into these powerful navigation tools. Read more about Adlib’s document enhancements in this blog post, or check out this white paper on automating document conversion and enhancements.