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Re: A case for artifacting bullets in unordered lists in PDFs

for

From: Jonathan Metz
Date: Jul 23, 2013 10:59AM

Hi Olaf,

Thanks for responding.

>-characters used for bullets in bulleted lists (from my point of view)
>are not an accidental by-product of doing page layout / pagination (they
>exist also
>-on web pages, where no such layout / pagination happens)
>-by definition this implies that they cannot be artifacted just because
>they happen to be in front of list items


My reasoning comes from a discussion I had a while ago on LinkedIn about
what to do with custom bullets in Links. It was suggested that if they
provided no semantic meaning, Bullets should be hidden from screen
readers. I guess the school of thought being that if it had numbers, it
would be more important to listen to them. But I see yours (and others)
point about how creating a Bullet for a list creates semantic context for
what kind of list it is.

>
>- PDF and PDF/UA require that such bullet character is put inside a <Lbl>
>tag

The problem is, PDF 1.7 never explicitly states that a <Lbl> tag is
mandatory. The only language it provides is through the ‘ListNumbering’
attribute (under Table 347), which says "Lbl elements (if present) contain
arbitrary text not subject to any numbering scheme”. I understand that
ListNumbering is about what kind of L it is, but this was the only
indication I could find where 32000 mentions the Lbl’s presence. Why would
it mention ‘If Present’ if it couldn’t possibly also be ‘Not Present’?
Could I use the ListNumbering to specify this is an unordered list instead
in previous documents? Where would that have gone? I digress...


ISO 14289 only states "Lbl and LBody tags may be included”. The Tech Imp
guide mentions that these things should be hidden from view.

Whatever, I see your points and will change my recommendation regarding
Bullets in PDFs.


>- on the content inside the Lbl (not on the Lbl, please).



If I change the properties in a content box, it affects the tag it resides
in. Should I nest these inside <Span> then?

Again, thanks for the advice. I’ll suggest otherwise from now on since I
have real world examples of a request for bullets in a list. If there is a
list without bullets, how would I provide the ListNumbering Attribute?

Thanks!
Jon