Some weeks ago, I wrote a piece about the signs that most irritate me because of their linguistic imprecision. Things like "Dogs must be carried on the escalators" and "Gentlemen lift the seat". Since then, there has been a steady trickle of readers' letters either adding their own pet hates or, in some cases, simply begging for elucidation.

Kate Coughlan, a New Zealander cast linguistically astray in Oxford, was worried about "Altered Priorities Ahead". Rather like those signs near airports that warn of low-flying planes, it leaves one wondering just what action one should take - especially if you have never been there before and do not know what the priorities were in the first place. If the intention of the sign-writers, however, is just to let you know that none of the other drivers approaching the next roundabout know what they're doing either, then it could serve a valid purpose.

Ms Coughlan is also puzzled by shops displaying signs saying: "We stock fat binders", a puzzlement that reminded me strongly of a sign in a shop window I spotted in Cambridge advertising: "Cleaner woman required".

Geoffrey Burnaby is perplexed by "No public access beyond this point", a sign which never identifies the precise location of the dimensionless point referred to, nor the direction beyond it in which one may not publicly go.

Harold Brend has always enjoyed "Watch batteries fitted while you wait", which he says may be seen at Oxford Circus underground station. "I have supposed this to refer to some arcane entertainment devised by London Transport to amuse passengers waiting for delayed trains," he says, but is a little confused because he had always assumed that the trains were run on mains electricity.

Tom Hopkinson rightly takes me to task for suggesting that "Please do not stand on the left" would be an improvement on "Please stand on the right". he points out that it would only encourage people to sit or lie down on the left. We shall therefore propose to London Underground that the signs should be altered to: "Passengers who wish to decrease the time of their journey on the escalator by ambulating in its direction of motion during their escalatorial sojourn are exhorted to do so on the left of the stair; passengers who wish to maintain zero velocity with respect to the escalator should occupy a position on the right; other passengers should seek assistance from a member of staff."

Best of all, however, James Warsher wrote to us all the way from Cambridge, Massachusetts, with the following story about the late Sir John Elliot, who was General Manager of the (pre-nationalisation) Southern Railway.

"Strolling across the concourse at Charing Cross, Sir John heard the announcer intone: `Due to a points failure, the following trains will be delayed ...' Sir John walked over to the announcer's booth and said: `There's a good fellow. Listen. Only trains and babies are due. Everything else is owing to.' Which is why, even today, one hears on Charing Cross and other ex-Southern stations, `Owing to a points failure ... '"