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Re: Reference tag with ALT text

for

From: Duff Johnson
Date: Apr 23, 2020 7:29AM

> Mmmmm....I think Alan may be trying to get at the question of whether this syntax may be acceptable in cases when there is a single note that is referenced multiple times. And in such cases, I'm not sure that the PDF Association's best practice guide is helpful? In 4.2.7.3 Creation (on page 37) of their guide, they imply that their recommendations are only fully reliable when:
> - the label is not repeated elsewhere in the document, or
> - the same-labelled <Note> follows the <Reference> in the logical reading order.

That is correct. The problematic use case you mention (a single note referenced multiple times) is due to a weakness in the PDF 1.7 specification. This was addressed in PDF 2.0 (published in 2017), but implementers have yet to catch up.

The Best Practice Guide you referenced is all about PDF 1.7, as this is still (today) typical PDF technology.

Duff.