Recognizing that we will eventually re-create the Publication Formats as technology changes, we still want to respect the archival aspect of the Series and minimize reformatting where possible. This suggests that each publication format should be designed to minimize the need for future re-formatting (let's set this for 5 year intervals).
ISO standard 32000-1 (not Adobe 1.8 nor the 2.0 draft)
Currently also contemplating:
- PDF/A - series of ISO 19005 standards
- Pros: Will minimize issues such as font availability and lessen the need for future reformatting
- Cons: Likely more expensive to implement
- PDF/UA - ISO 14289-1
- Pros: all the usual good reasons to make documents more accessible
- Cons: relatively new; uncertain as to long term support; unsure if this is necessary given the intent to make HTML docs follow W3C Accessibility Guidelines - Deciding NOT to go with the PDF/UA standard
Useful information regarding PDF/A available on PDF/A, PDF for Long-term Preservation -- See “Sustainability Factors”
PDF/A - from the 3DPDF Consortium
Note (from http://www.dlib.org/dlib/november10/noonan/11noonan.html
The PDF/A-1 standard provides two levels of compliance: PDF/A-1a denotes "full compliance" and ensures the preservation of a document's logical structure and content text stream in natural reading order. The text extraction is especially important when the document must be displayed on a mobile device (for example a PDA) or other devices in accordance with Section 508 of the US Rehabilitation Act. In such cases, the text must be reorganized on the limited screen size (re-flow). This feature is also known as "Tagged PDFs." PDF/A-1b denotes "minimal compliance" and ensures that the text (and additional content) can be correctly displayed, but does not guarantee that extracted text will be legible or comprehensible. It therefore does not guarantee compliance with Section 508 [4].
More about PDF tags http://help.adobe.com/en_US/acrobat/X/pro/using/WS58a04a822e3e50102bd615109794195ff-7cd8.w.html
List of assumptions (HF)
1 - There are valid use cases where people prefer PDF over HTML. 2 - Self-contained outputs are better for readers of RFCs because they presuppose fewer configurations and installations on the reader's system. 3 - I have a goal of minimizing the need to re-publish RFCs to get the format up to date (saves time and money to avoid this when reasonably possible)
With that, I'd like to propose that we follow the PDF/A1-a standard for the PDF publication output.
Anticipated questions:
1. If you are suggesting PDF/A, why not PDF/A-2 or PDF/A-3?
Based on conversations with experts at Adobe, PDF/A-2 and A-3 are not commonly supported at this time. In addition, both offer features that are not required for RFCs; the goal is to keep this as simple as is reasonable given our requirements.
2. Why conformance level A instead of B or U?
Level A guarantees text extraction and searchability and preserves the structure and content in such a way that it can be easily read across a variety of deices. (See http://www.dlib.org/dlib/november10/noonan/11noonan.html)
3. How do the tags being used for XML and HTML translate or convert to PDF tags?
Work still needs to be done to understand this (See the list of Standard PDF tags here: http://help.adobe.com/en_US/acrobat/X/pro/using/WS58a04a822e3e50102bd615109794195ff-7cd8.w.html)
