This is from an obituary, published on Tuesday, of Carl Elsener, the boss of Victorinox, the company that makes the Swiss Army Knife: “The ‘war on terror’ after 9/11 had seen sales of the Swiss Army Knife plummet by up to 50 per cent after they were prohibited from airline hand baggage.”

No disasters here, but a couple of infelicities to note. First, “prohibited from hand baggage”. After “prohibited from” you expect to see a verb – prohibited from doing something – not a noun, such as hand baggage. A knife might be excluded, barred or banned from hand baggage, but not prohibited.

Such conventions of usage are arbitrary, but getting one of them wrong may bring the reader up short, like a mis-spelling.

Of course, with time, they can change. One such change seems to be under way now. It concerns the verb “forbid”. Twenty years ago, “forbid to” was universal. Today, “forbid from” is also used. It may be that in another 20 years, “forbid from” will be the norm, and “forbid to” an archaism. I guess one reason for this shift is probably an analogy with “prohibit from”.

The other oddity is “sales plummeted by up to 50 per cent”. The reader’s reason can comprehend what is meant, but the imagination struggles to form a picture of what is happening. We seem to be moving down and up at the same time.

And what does “up to 50 per cent” mean anyway? Is it nearly 50 per cent; or 50 per cent in some places and less in others; or what? When you see the words “up to” followed by a figure, you are entitled to suspect that something is being fudged.

Location, location: A news story published on Wednesday informed us that the US would hold talks with the Taliban “at a location in Doha, the capital of the Gulf nation of Qatar”. Well, I am writing this on a train at a location near Amersham, and in an hour I will arrive at the offices of The Independent at a location in Kensington. What is the difference between “at a location in Doha” and plain old “in Doha”?

“At a location” is presumably shorthand for the cliché “at an undisclosed location”, but the short version looks absurd.

“What are you doing there, Gunner Milligan?” barked an officer in the wartime Royal Artillery. The youthful future Goon retorted: “Everybody’s got to be somewhere, sir.”

Right-on peer: Trevor Cox writes in to point out the following, from an article in last week’s magazine about a campaign to give women equal rights of succession to peerage titles: “Women are, by statute, considered unsuitable inheritors. It is one of the last pieces of gender discrimination enshrined in common law.”

Well, it must be either statute or common law; it can’t be both. A lawyer I consulted thought it was probably common law, but this is a pretty arcane area.