It’s a cliché of our trade that if computers stopped functioning, everybody’s life would be a lot simpler. It’s also a cliché that we simply couldn’t manage without them.

I was reminded of this apparent paradox last week, when I discovered that I may have overlooked something in my examination of RFID in business: I may have overlooked the importance of history.

RFID technology is widely used to keep track of stock as it makes its way through the supply chain. The technology is very good at this, but there’s a problem. Suppose you sell hair shirts, and your customers start complaining that they are comfortable; obviously, you’re using the wrong sort of hair.

You can ring the factory and say: “Where did you buy the hair?” and they’ll say: “We don’t buy hair. We get hair-shirts knitted by old monks in Tibet. And they probably get it ready-carded from an international supplier.” And they probably get it from co-operatives.

Your problem: to find how the soft, delicately scented locks are getting into the supply chain. To the rescue comes the Electronic Product Code Information Service (Epcis) from an operation called Historic Futures.

Naturally, it all turns out to be XML. What isn’t, these days? Electronic product codes are starting to have embedded data in them, which can tie into embedded data from suppliers, who in turn embed data from their suppliers to the point where you can actually look at a map of all the suppliers of hair to the hair processing and carding industry, and discover that the unacceptably soft and soothing hair is all sourced from a district called Rapunzel Towers.

Or, perhaps more mundanely, you find that you’ve bought a lot of “organic” potatoes and the audit trail leads to a well-known maker of superphosphate fertiliser; or that 10 percent of the tier seven farmers behind your ethically sourced leather are involved in dog-meat supply.

This kind of traceability is of critical importance to big retailers like Wal-Mart.

And it does leave you wondering: just how the heck would you operate a big retail operation without XML and computers?