When the Queen pins on a large brooch she's clearly going off to work, but on practically any other woman today a large brooch says: 'I don't work and my role model is Margaret Dumont'. When Keith Richards shoves several hundredweight of silver on his hands and wrists he's off to work too, but in a corporate or professional environment it'd say: 'unemployable Stonehenge/Glastonbury traveller type'.
Jewellery's really difficult at work. It can say some very odd things about men and women. For women, it can send a variety of inappropriate messages such as secretary-bird (various H Samuel nine-carat gold slivers hung about her). It can say 'Sloane, I'm-not-really-working-here', it can say 'office-Geisha'. Any which way, it's difficult.
I always remember a CEO's PA at a FTSE company who was terrifically correct, almost prim, but whose personal life you speculated on because she wore an ankle chain. An ankle chain! It says slave girl or 1950s Shepherd's Market. That ankle chain totally diverted all comers from businesslike thoughts.
There is officially sanctioned jewellery. Earrings are OK - some of them. Smart management women can always wear this year's version of the newsreader earring - medium-sized studs usually involving pearls - but anything dangly is deadly, and big hoops have a curious Joan Baez feel to them that's best avoided. Two rows of pearls can also be worn in a variety of quite credible ways provided they're set off by down-dressing - well-cut trousers and so on.
But for a lot of younger working women now the jewellery question hardly arises in the office. They wear active clothes; they move around a lot; they use a lot of technology; they carry a laptop and a mobile; and so jewellery just doesn't fit in their working lives.
The jewellery focus is shifting. A lot of men and women who'll soon be in the management market - they're currently students and casuals of various kinds - are heavily pierced and tattooed. There are an awful lot of educated young middle-class people with elective holes in them at a variety of visible and invisible points. And there are an awful lot of educated young middle-class people with permanent inks seared into them all over. What happens when they get on the management chain? Does all the visible silver come out, or is it just scaled down? I think we should be told.
At lunch with Dan, the British CEO of a German-owned multinational of legendary stodginess, I suddenly noticed his ear. Then I started to see them everywhere - the ancient ear piercings. I know a number of deeply serious careerist men pushing 40 whose pieced lobes betray their earlier lives as students, hopeful musicians and so on. But they've only got one hole - and it was obvious when they joined the management chain that the earring had to go. The trade-off's less clear now, particularly in the new business areas.
There's another set of jewellery issues for men, of course. Men have been wearing metal 'brightwork' - jewellery with a functional alibi such as shoe trims, belt buckles and blazer buttons - for years. Most of it looks deeply dated - very early '70s - and distinctly naff. A monk's buckle on a shoe is iffy, snaffles only acceptable on real old Gucci loafers.
Big square-toed numbers with silver bars are strictly for the lads.
Equally, those 'designer-brand' belt buckles in bright lacquered brass say you've got about as much design sense as a magpie. Blazer buttons come in a range of naffness but the problem is easily addressed - don't wear blazers.
As for hand and wrist stuff, in most areas of corporate and professional life you're better off without. Disregard all fashion features about big biker revival silver rings and bracelets. Disregard excited pieces about the Shaft/Superfly revival and the 42nd-Street pimp jewellery that goes with it. Unless you work in the fashion, entertainment or sex industries, people absolutely won't get the point and you'll look silly.
That just leaves sanctioned kinds of rings. With rings you've got the 'band of commitment' - a plain gold wedding ring - and the signet ring, the absolute spiritual centre of Sloane dressing. Signet rings should be old 'soft' gold with a nice worn crest if you wear them at all. Not big monsters with a cabochon thing at the centre, or imaginative initials.
But I'm beginning to think they're better kept for the evening too, when the League of Gentlemen holds its secret seances in St James's.
Peter York, in his persona as Peter Wallis, is managing director of consultants SRU e-mail: firstname.lastname@example.org.