The archiving standard, and who supplies what

The 10 claims

Two questions settle which one you want. Does the document have to be read out loud by software? Does it have to carry another file inside it? If neither, the plainest claim is the right one.

What every archival document here carries

This holds whichever part is claimed. Nothing on it has to be asked for a second time.

• The document carries the fonts it uses, so the page displays the same on a machine where those fonts were never installed.
• An output intent is written whether or not one was asked for, so the greys and the reds mean the same thing on the next screen as on this one.
• The document's description — its title, the moment it was written, the part it claims and the year of that edition — is written into the document, and the claim is stated in the place the part being claimed requires.
• A report can be asked for before anything is written: it comes back with every finding at once, each naming the published text it answers to and the font, layer, page, link, field or cell it is about.
• A document that claimed a part and breaks one of its rules is refused rather than written wrong, and the refusal names the rule.
• Everything the document leads to is inside the document. Every part of the standard allows an instruction opening a file that sits beside it instead; the team declines that instruction under an archival claim, so the document stays readable on its own the day the folder around it is gone.
• The verdict belongs to two checkers that had no hand in writing the file, veraPDF and Ghostscript, and both are free to run on the document you download, from your own machine. Before a change enters the library or the service, every document claiming an archival part goes to veraPDF, and a refusal stops the check where it stands.

What every part of the standard rules out

Each of the bans below removes a way a document could stop being readable later; each edition's own page says which ones it adds and the few it relaxes.

• Encryption of any kind: an archived file opens without a password.
• Programs inside the document, and anything that launches a program.
• Sound, video and anything else that is not ink on a page.
• Anything the document does not carry itself: a font, a picture or a page that would have to be fetched from an address.
• A font named but not carried, whether it is one of the fourteen reading software is assumed to own or one of your own.
• An annotation that does not carry the drawing of how it is to appear.

The four editions, and the page each one has here

The family has been published four times, in 2005, 2011, 2012 and 2020, and every one of the four is still in force: whoever receives the document names the edition they require. Each has a page of its own here, saying what that edition asks for, what it rules out, and where it stands with us today.

• PDF/A-1 — ISO 19005-1, 2005 The first edition, published in 2005, is the one that set the rule the four editions have applied ever since: everything the document needs to be read is inside the file. The fonts are in it, the colours are described in it, the pictures are included in it. Nothing to fetch elsewhere, neither over the network nor on the machine that opens it.
• PDF/A-2 — ISO 19005-2, 2011 The second edition, published in 2011, holds to the same rule as the first and lets a document use what the format had gained in the six years between them.
• PDF/A-3 — ISO 19005-3, 2012 The third edition, published in 2012, differs from the second by a single clause — and that clause is the reason electronic invoicing across Europe is built on it.
• PDF/A-4 — ISO 19005-4, 2020 The fourth edition, published in 2020, is the first built on the current version of the PDF format. It simplifies the claim rather than adding to it.

The eight families

• Which part of the archiving standard to claim The archiving standard is a family, not a single rule. Four of its parts can be claimed here, ten claims between them, and choosing takes two questions.
• Every font the document uses is embedded in the file A document that carries its own fonts opens the same way on a machine that has never had that font installed. That is the first thing the standard asks for, and the one that changes the file most.
• Colours that mean the same thing on every device Numbers on a page become a precise colour only once the device they were chosen for is named. An archival document carries that device's profile inside it.
• A page that comes out the same for everyone The promise of an archival document is that the page read today is the same page decades from now. It holds only where the file settles everything the page shows, leaving nothing to the reading software.
• The document says what its marks stand for The content of a page records where each letter is drawn, not what it means. Level A of the archiving standard and the accessibility standard (ISO 14289) ask the document to say it: which group of words is a title, which is a paragraph, and in what order to read them.
• A document that carries other files inside it ISO 19005-3 (PDF/A-3) exists because a document sometimes has to carry another file inside it, and that file has to come back out years later, whole.
• What the file says about itself A document still opened decades from now is found again by what it says about itself, not by the folder it happened to be in.
• Checking the claim, before and after Claiming a standard is one line inside the file. That line is not enough on its own: for the claim to be worth anything, an independent checker — one you run yourself, and one the team did not write — has to accept it.