Despite its relentless modernising, Germany retains some traditional social niceties that can be difficult for foreigners. A common pitfall remains whether to address someone as Sie (formal, for older people, superiors, colleagues in stuffier workplaces, strangers) or du (informal, for relatives, close friends, children, pets).

I first encountered this dilemma when teaching at a business and language school in Frankfurt in the 1970s, although it didn’t unsettle me as much as it did my colleagues, because the broad Yorkshire we spoke back home meant I had grown up using ‘thee’, ‘thy’ and ‘thine’ daily.

However I was bemused to discover back then that more conservative Germans even had a Friendship Ceremony at the point when the older or ‘superior’ person in the relationship proposed that it was time to move from Sie to du. This usually involved a glass of wine, linking arms and the exchange of respective forenames, after which the couple began to duzen one another.

This and other rules of German etiquette were set out originally in a book published in 1788 by Adolph Freiherr von Knigge. It was serious subject matter at the time, and von Knigge had previously written about Kant and Rousseau. Even today the rules are updated for modern usage by the Knigge Society, whose recent proclamations have included the correct way to end a relationship by text message and how to deal with a runny nose in public.

The Society has also run a campaign against cheek-kissing in the workplace, which is perceived as un-Germanic. Today’s president of the Knigge Society, Dr Hans-Michael Klein (obviously a Sie to most of us) claims to have had 50 e-mails in a year complaining about the practice, on the grounds that there was an erotic or predatory aspect to it.

Herr Klein reported that in Europe, people expect a ‘social distance zone of 60 cm’ and recommended that this should be observed. Such precision is very Germanic, as is Herr Klein’s advice that office staff indicate their preference ‘with a little paper message placed on their desk.’

Of course, employees would still be at risk from predatory cheek-kissers when away from their desks. My suggestion to the Knigge Society, offered at no charge, would be colour-coded name badges: red for no-cheek-kissing-at-all, green for don’t-mind-if-I-do and orange for try-it-and-see.