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

for

From: Jonathan Metz
Date: Jul 23, 2013 3:31PM

>> you can easily have lists without a label character in from of the list
>>items.


[Me] Hi Olaf. I¹m having difficulty understanding you here. Can you
extrapolate this for me?



>[Me]ISO 14289 only states "Lbl and LBody tags may be included².

it's kind of just repeating ISO 320001- here:

Excerpt from ISO 32000-1 (PDF 1.7), 14.8.4.3.3, Table 336
>(List item) An individual member of a list. Its children may be one or
>more labels, list bodies, or both (structure types Lbl or LBody).

the idea here is to keep things very open; who says the list item label
must always be in front of the list item? Maybe in some fancy list it's in
the middle of list items, and some list item body before and after. Naybe
it has label in front and after each list item? And maybe there is no
label at all because the list appearance is created by some other visual
mechanism, like a box around each list item

[Me] I wasn¹t trying to imply that there was some fancy order to list
structure, just that ISO 32000 says it *may* include something not *must*
include. ŒMust¹ means a requirement, whereas may implies a suggestion.

OrŠ Are you saying that theoretically it would be fine to have an L tag
and what is inside of it is the bullet and content of the list?


>[Me]The Tech Imp
>guide mentions that these things should be hidden from view.

where does it say so? I must be missing something.

[Me] You must have missed it from the beginning of the email chain:

"In a unordered list without Lbl elements (which is permissible) the value
of ListNumbering should be "None". In such cases the graphics objects
representing the list's labels should not be contained in the logical
structure and should be marked as Artifacts. - See more at:
http://www.aiim.org/Research-and-Publications/standards/committees/PDFUA/Te
chnical-Implementation-Guide#Section7²

Again, thanks for your help,
Jonathan



On 7/23/13 5:10 PM, "Olaf Drümmer" < <EMAIL REMOVED> > wrote:



>Hi Jonathan,
>
>>>
>>> - 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.
>
>PDF 1.7 describes syntax and how to use it for a certain purpose. It very
>clearly states that something that is a 'label' (bullet, number for a
>list item, term to be defined for a dictionary list, Š) is put inside a
>Lbl tag.
>
>Admittedly PDF 1.7 is not using strong normative language. But by
>ignoring the statement that labels go inside a Lbl tag, one is simply not
>following the rules of the syntax.
>
>PDF/UA uses stronger normative language by stating that one must always
>use tags, and that one must use the right tags:
>
>Excerpt from ISO 1428901, 7.1:
>> "Content shall be marked in the structure tree with semantically
>>appropriate tags Š. "
>
>
>> The only language it provides is through the ŒListNumbering¹
>> attribute (under Table 347), which says "Lbl elements (if present)
>>contain
>> arbitrary text not subject to any numbering scheme². 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 Lbl¹s presence. Why
>>would
>> it mention ŒIf Present¹ if it couldn¹t possibly also be ŒNot Present¹?
>
>you can easily have lists without a label character in from of the list
>items.
>
>> Could I use the ListNumbering to specify this is an unordered list
>>instead
>> in previous documents? Where would that have gone? I digressŠ
>
>that's what the None value is for:
>
>Excerpt from ISO 32000-1 (PDF 1.7), 14.8.5.5, Table 347
>> None: No autonumbering; Lbl elements (if present) contain arbitrary
>>text not subject to any numbering scheme
>
>
>> ISO 14289 only states "Lbl and LBody tags may be included².
>
>it's kind of just repeating ISO 320001- here:
>
>Excerpt from ISO 32000-1 (PDF 1.7), 14.8.4.3.3, Table 336
>> (List item) An individual member of a list. Its children may be one or
>>more labels, list bodies, or both (structure types Lbl or LBody).
>
>the idea here is to keep things very open; who says the list item label
>must always be in front of the list item? Maybe in some fancy list it's
>in the middle of list items, and some list item body before and after.
>Naybe it has label in front and after each list item? And maybe there is
>no label at all because the list appearance is created by some other
>visual mechanism, like a box around each list item
>
>> The Tech Imp
>> guide mentions that these things should be hidden from view.
>
>where does it say so? I must be missing something.
>
>>> - 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?
>
>I believe this would be the right approach
>
>
>
>Thanks,
>
>Olaf
>
>>>