The people’s encyclopedia, Wikipedia, notes that the phrase four-letter word 'refers to a set of English words which are considered profane, including popular or slang terms for excretory functions, sexual activity and genitalia' which sets the tone for Dylan’s cynical take on love. A treatment taken to the extreme by Seattle band, The Blood Brothers with their memorable Love Rhymes with Hideous Car Wreck.

Wine is another four letter word. Which is quite appropriate, as some consider the fermented fruit of the vine profane, and it can definitely lead to excretion and sexual activity, if enough is consumed. In Afrikaans, a more economic three letters (wyn) is used and sure enough there a plenty of three-letter Afrikaans profanities, with kak my favourite. The parsimonious Dutch also swear by three, although wijn has four – but then an argument could be made that ij counts as one on the grounds of customary simultaneous usage.

Latin, a language currently undergoing an unexpected revival, uses the three letters vin to refer to wine and a popular insult among classicists is 'es vir litterarum', i.e. you are a man of three letters. The French, as usual, break the rule, as their name for wine, vin, has three letters while the quintessential French profanity merde is euphemistically referred to as 'the five letter word.'

The Germans are back on message: wein has four as does the phrase 'sit down on your four letters' referring to popo – bum in baby parlance. As are the Spanish: vina is a four-letter Spanish vineyard and vino is the stuff that comes from grapes grown in it, while calling a girl 'a four-letters' means she is sexually uninhibited.

In Polish, wine is wino which explains the origin of the term for Bowery bums and sure enough 'the four letters' or cztery litery is the Polish euphemism for dupa.

The only place the four-letter rule does not apply is in winespeak, where four letters do not give sufficient degrees of freedom for pretence and ego inflation. Six seems to be a minimum requirement for the 'whiffs of cassia' brigade that clog up wine guides. Oh, for a return to the days of Cole Porter when,

Good authors too who once knew better words
Now only use four-letter words
Writing prose
Anything goes.