For those of you in the accessibility world who struggle with the “Only one H1 in a PDF document” theory, I feel your pain. If you are new to accessibility, then you have undoubtedly come across the two schools of thought on this topic. On one hand, we have those who will will draw the line and say “Only one allowed.” On the other hand you have those that say, “As long as you follow the Parent/Child structure, you can have any number of H1 tags as long as it makes sense to do so.
Where did it come from?
Coming from a web background, I can completely understand how some might come to the conclusion that you can only have one H1 tag in a PDF. Because, in fact, in an HTML document it is absolutely clear that you should only have one H1 tag on your page. Since WCAG (Web Content Accessibility Guidelines) came first, it is very understandable why some insist on this “Only one” rule. But PDFs are a different type of content. While many of the WCAG 2.x principals do apply to the content in a PDF, this is one rule that does not. PDF/UA guidelines do not limit documents to a single H1 tag. But don’t just take my word for it.
H1 tags – the definitive word?
In a recent webinar Andrew Kirkpatrick (Adobe Head of Accessibility) gave his word on topic by answering the question “Some clients require there is only one heading at level 1 in a PDF document. Is this a hard rule in PDF/UA or is it just the client’s preference?” Andrew responded, “PDF/UA does require that headings are nested properly. You cannot jump from a Heading 1 to Heading 3 but you can have multiple Heading 1s if that is appropriate for that document… obviously if you have a client who says you can only have one heading one, then, you know, that is — if that is what they want then that is fine. But in order to conform with PDF/UA or WCAG or Section 508, that is actually not required. PDF/UA is more strict because they require that you nest them appropriately whereas the other standards don’t currently require that.”
The takeaway
We have clear direction and a source cited. So we are good, right? Well, yes and no. In the end, the client is always right. If the agency you work for (i.e. Health and Human Services) require that your documents contain a single solitary H1 tag, then you should follow their direction. The truth is, starting your section numbering at an H2 level in your word docs or mapping your styles to H2 tags in your InDesign documents only requires a quick adjustment. The key takeaway here is, know the rules before you play the game. Get clear direction from your company or the agency you are remediating or creating for before you start the work. Doing this when you start your document is far easier than fixing it in the tags tree on the PDF end of things.