## Post Office nerdview (capped)

Postal orders are a way for people in Britain to send money by post without having a checking account, but there is a fee, dependent on the face value of the order. For a postal order with a face value of more than £100 the fee is shown on the Post Office web page as "Capped at £12.50", which puzzled Matt Keefe. He wrote to me to ask if it was an instance of nerdview. Absolutely; that's exactly what it is.

Here's the table of prices as the Post Office gives it:

 Purchase value per order Fee payable £0.50 – £4.99 50p £5 – £9.99 £1.00 £10.00 – £99.99 12.50% of the face value £100 – to maximum of £250 Capped at £12.50

What an utter dog's breakfast of bad expository practice.

• Notice the completely inconsistent presentation of currency amounts (£0.50 vs. 50p, £5 vs. £10.00, and so on; the only reason for writing £10.00 is to contrast it with another value that needs the two places of decimals, like £99.99).
• Notice the inconsistency of first using the term "purchase value" and then using "face value" for exactly the same thing.
• Notice the redundant word "payable": all fees are payable, that's the whole idea — you pay them.
• Notice also the pointlessness of giving 12.5% to two decimal places instead of one (permitted visual confusion between 12.50% and £12.50). You wonder why they didn't use five decimal places, because under their rules the fee for a £99.99 postal order is technically £12.49875.
• Notice that there is no need to say "- to maximum of £250" because that maximum is made very clear elsewhere on the page, not least in the header, and in any case it would be implied if no entry in the table covered any larger amount.

And that phrase "capped at"? It's pure nerdview: the fact that the Post Office decided to cap the fee at 12.5% of £100 is a matter of internal policy; the public has absolutely no need to be aware of the notion of capping. All the user of the page needs to know is that for a postal order with a value between £100 and £250 you pay a flat fee of £12.50. It is an irrelevant historical fact that the Post Office derived this amount by capping the function f(x) = x/8 (used for face value x when 10 ≤ x ≤ 99.99) at the value attained when x = 100.

The table is a complete lesson plan in how not to present information to the general public.

Reluctantly doing the Post Office's work for it, without financial compensation (remember, this is in fact Language Log, not Post Office Administration Log), here is the table the way they should have written it:

 Face value Fee 50p – £4.99 50p £5.00 – £9.99 £1 £10.00 – £99.99 12.5% of the face value £100 – £250 £12.50

If the Post Office has any decency, it should send me an ex gratia payment for this work. I suggest £12.49875, sent by postal order. (The fee they will need to charge themselves, just in case you haven't got the calculator app open on your smartphone, will be £1.56234375. At the current exchange rate of £1 = $1.32695 — it changes every minute — that would be$2.0731520390625.)