Hi Linda,
I know, it's confusing. And there should be NO reason that the read order is different than the tag order...so ADOBE should sync the two or get rid of one and just let an "order pane" dictate both read order and tag order. But, if for now it is what it is, I've discovered these helpful tips:
- Layers can be used to control the "Read Order" in your PDF.
- The Articles pane can be used to control the "Tag Order" (or Tab Order).
- Personally, I don't use Layers to control my read order. But my read orders are never out of whack, therefore, I've never had the need. But, before the layers were the answer to read order, I discovered that even you only have ONE "Layer," the order can be controled/determined by the order in which you placed items on the page, meaning the first placed item is read first (in the read order) and the last item placed is read last (in the read order).
I've had some very complicated documents (like org charts) with stuff peppered all over the place. I merely used the Articles pane....and my read order mirrored the Articles pane....and my tags were perfect.
I hope this helps.
~Mary Helen
Yeowza!
Such a lot of mixed up info in this thread over the years. Let me take a stab at bringing some order to this discussion about reading orders. This will be long...
#1: The Tag Tree reading order (Tag RO) is most important because it is mandated by the PDF/UA-1 accessibility standard. Most of the assistive technologies on the market today are compliant with the PDF/UA-1 standard and, therefore, take their accessibility from the Tag Tree RO. They read the content in the order shown in the Tag Tree.
There are several methods in InDesign that control the Tag RO; here they are in order of effectiveness:
- Thread your stories from the 1st frame to the last as one story thread. That means each story thread will begin with the frame that holds the heading 1 (title) and be threaded to the successive frames through the last paragraph of text. In some designs, this is all it takes to have a fully compliant, beautiful Tag RO as well as perfects tags.
- Using a single frame per page, divided into multiple columns if needed, is a quick way to thread everything in the story. Using the Primary Master Text frame is a variation of that. But not all designs can be created with that single frame method — such as brochures, posters/flyers, fact sheets, newsletters, and other types of designs with lots of bits and pieces — so don't depend on using a single frame layout for everything, and ensure you learn how to "stitch" or thread frames together into logical stories.
- The Articles Panel doesn't really help much in terms of accessibility. There are many types of designs that don't need it at all, but some key times to use it are for complex designs, such as covers, flyers, posters, and info-graphics where you have a lot of bits and pieces to wrangle into a logical reading order. It can help improve your Tag RO, but it doesn't control it entirely. So if you have not threaded your stories (the first bullet), the Articles Panel most likely won't save your butt entirely.
- Note: If you use the Articles Panel, it will group together all the tagged elements in each story into an individual <Art> tag. That might make your tag tree look nice for us who can see tag trees, but it does absolutely nothing for accessibility. Not one assistive technology at this time (Sept 2021) recognizes the <Art> and announces it to the end user. It will be several years before this becomes a truly functional tag; we were just discussing it today in one of our ISO committee meetings for the PDF/UA standard and standards take years to develop and get published. Don't hold your breath waiting for this to happen.
- Another note: But there's nothing wrong with future-proofing your PDFs to have the <Art> tags in it for each story.
- Watch out for these Quirks of the Articles Panel
- — Once you drag one element, frame, graphic, etc. into the Articles Panel, everything must be dragged into it. It's an all or nothing tool. If something is left out, it will become untagged content in the PDF, not artifacted, but not accessible either. The left-out items are in Zombie-land...neither alive nor dead and often fail accessibility checkers.
- — For each Article you create in the panel, check its option to Include When Exporting. Easily missed when you're on deadline and so frustrating when it doesn't tag your stuff! Wish Adobe would set its default to ON so that we didn't have to think about this one. Don't foret to set it for each Article.
- — Set the panel's options to Use for Tagging Order in Tagged PDF. This is in the panel's options drop-down menu. Set this once and it controls all articles in the panel.
- The last item that could affect the Tag RO is the Architectural Order — you see this in InDesign via the Layers panel, and we see it in the Order panel in Acrobat. In complex designs with items overlapping each other, the stacking order in Layers can affect the Tag RO. Not always, but sometimes. (See more in #2 below.)
#2: The Architectural Reading Order is the next most critical one to control. Although most compliant assistive technologies use the Tag RO, many instead use the original reading order of PDF: the Architectural RO, which has been in PDFs since day one. Tags are a more recent addition to the file fomat.
It's also the RO used for cross-media publishing and greatly affects EPUBs, HTML, XML, and other publishing technologies you could export your InDesign layout to.
You know this as THE Order panel in Acrobat — the blue "z" tool. Why someone at Adobe named it THE Order panel is beyond me; there are 4 different reading orders for accessibility in PDFs, and this is not THE main one or only one, but instead it's tied for second place. (Note that the 4 ROs correspond to the 4 items in my post.)
Several techniques to control the Architectural RO, in order of ease and effectiveness:
- Remember, every piece or frame you place in your layout will be another element to control in the Layers Panel.
- Therefore, minimize the number of frames you use. Try to simplify your design, or the way you construct your design, to use as few frames as possible. This is an ideal time to consider using that single-frame-per-page technique above (such as a primary master frame) — it keeps order in your Layers Panel, and produces nice clean Tag ROs and Architectural ROs in the PDF.
- Drag/Drop elements up/down the layers panel to control the RO. This panel's RO is read bottom up.
- Flatten your layers in InDesign.
- Better yet, use just one layer in InDesign. The more layers you have, the more screwed up your PDF will be.
#3: The TAB Reading Order.
I know it's called the TAB RO, but most assistive technologies don't use the TAB key on their keyboard to invoke it. Other keys they might use, depending upon their technology and their user preferences: up/down arrows, return key, a double-puff through a puffing straw, a nod of their head, a voice command ... whatever action that allows them to tell the technology to advance forward one paragraph or line or form field or whatever. Just remember that TAB RO doesn't necessarily mean the user is using the actual Tab key on their keyboard.
These 2 InDesign techniques, used together, control the TAB RO:
- Thread your stories (see #1).
- When exporting to Interactive PDF, click the option to Use Structure for Tab Order. Translation: follow the Tag Tree for the Tab RO.
#4: The Form Fields Reading Order is used only in PDF forms, so let's skip this one until you're in a PDF forms class.
Hope this helps.
Hmm. Looks like I just wrote a new handout for my Accessible InDesign class on Friday <grin>.
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