Definition of “long document” in the context of PDF2 (Creating bookmarks in PDF documents) for Success Criterion 2.4.5 Multiple Ways

[rraddatch]

Hello,

In the PDF2: Creating bookmarks in PDF documents technique, the following statement appears:

“The intent of this technique is to make it possible for users to locate content using bookmarks (outline entries in an Outline dictionary) in long documents.”

Could you please clarify what counts as a “long document” in this context?
I couldn’t find an explicit definition in the WCAG Techniques themselves.

In the Making Content Usable for People with Cognitive and Learning Disabilities – Design Guide (section 4.4.8), it says:

“Long Documents have 300 words or more.”

Can this 300-word threshold be considered relevant for PDF2 as well,
or is “long document” understood differently there (for example, based on number of pages or sections)?

If there is an official WAI interpretation, it might be helpful to include a short note in the technique to reduce ambiguity.

Best regards,
Radoslav Ďurač

[DuffJohnson]

Beyond "long" documents PDF bookmarks have great utility for navigating heavily subdivided documents (for example, documents with many headings) irrespective of the document's length.

In the past I've recommended that bookmarks be provided for any document of >10 pages or >10 headings, but these numbers are (a) arbitrary, and (b) general purpose, not conceived for specifically accessibility-related purposes.

Another consideration is discoverability. PDF allows an author to configure a PDF such that the bookmarks are displayed when the file is opened - this should be a general recommendation.

As a starting-point I suggest altering this text to something more like:

The intent of this technique is to make it possible for users to locate content using bookmarks (outline entries in an Outline dictionary) in long documents (those exceeding a few pages) and documents with many subdivisions. In addition PDF files that include bookmarks should be configured to display the bookmarks when the file is opened.