[rfc-i] character sets, Bug in RFC Search page...
lrosenth at adobe.com
Mon Oct 2 07:59:16 PDT 2017
According to RFC 7995:
For RFCs, require PDF/A-3 with conformance level "U". This
captures the archivability and long-term stability of PDF 1.7
files, mandatory Unicode mapping (Sections 126.96.36.199.2 ("Unicode
Mapping in Tagged PDF") and 9.10.2 ("Mapping Character Codes to
Unicode Values") of [PDF]), and many of the requirement features.
PDF/A-3 requires that *all* fonts be embedded – so this should never be a problem.
On 10/1/17, 9:28 PM, "rfc-interest on behalf of Martin J. Dürst" <rfc-interest-bounces at rfc-editor.org on behalf of duerst at it.aoyama.ac.jp> wrote:
On 2017/09/28 03:04, Toerless Eckert wrote:
> On Wed, Sep 27, 2017 at 05:53:48PM -0000, John Levine wrote:
>> Those are buggy PDFs. A PDF is supposed to contain all the fonts it
>> uses beyond a small standard set, but there is a lot of PDF crudware
>> that wrongly assumes that whatever fonts it finds on the machine where
>> it's running will exist everywhere.
> I have stopped trying to really understand all those details for the last
> two decades, but i fear what you describe sounds like the original intention
> of adobe when they thought fonts embedded in PDFs could not be extracted
> and (illegally) be reused outside of the PDF. Once that hack happened (2 decades ago ?),
> the problem of licensed/payware fonts and their use has AFAIK lead to
> less inclusion of fonts into PDF.
For us, that should be irrelevant, because the fonts that we are
(planning on) using are open source, and can be embedded without
problems. Also, as far as I understand, the variant that we choose for
the official PDFs actually requires that all fonts used (except for a
very small base set) are included.
P.S.: In addition, please note that font embedding usually uses
subsetting, and our documents have very few non-ASCII characters, so the
additional memory needed for font embedding isn't much of a deal.
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