I’ve never really noticed before how over-indexed even common documents are. Maybe it’s just that we’ve become more sensitive to these things recently, but when I recently renewed my car’s tax disc (for non-UK readers: the document that shows your car is legally on the road) that I realised exactly how much numeric information appears on the document: There’s some “expected” information that really has to appear: names, addresses, car registration numbers, fee, and the like (which I’ve blurred). But the real action is on the counterfoil — a document you don’t have to keep, are never asked to produce, and will basically never be seen by anyone again. Let’s start with the long sequence of numbers (1)  at the top left. Two groups of these numbers are repeated bottom right as (3) and (4); three groups are distinct and don’t appear anywhere else. There’s a long issue number for this document bottom-left (2). At the bottom right, (6) also appears on the disc itself as (8) — in fact the only number  that makes it onto the tax disc itself, although there’s also a barcode in the centre. As if this wasn’t enough, and despite all the numbers being printed in what is clearly a machine-readable font, there are two QR code. In the interests of science I scanned them both. (6) repeats (5) (and therefore (8)), but (7) was too small to scan with a cellphone QR code reader: it’s visibly different to (6), though. So this is eight distinct pieces of information, in the main all dutifully recorded only to be discarded when one detaches the tax disc from the counterfoil to fit it. What is it all? Since we don’t have ID numbers in the UK, none of the numbers relate to me directly. I can understand a single registration number for the tax disc — although even that’s a bit redundant when you can query the tax status of a vehicle online to check whether the disc is genuine or not — but the rest mystifies me, as does the use of three machine-readable formats on one document. I’m not worried about the volume of information per se, as it’s being discarded and — more especially — it doesn’t seem to relate to me or my identity in any way, but I am curious as to why it all appears in the first place and what purpose any of it serves.