You change a great strapline at your peril.

So when news emerged of Carlsberg's new global slogan 'That calls for a Carlsberg', we all scratched our heads. What was wrong with 'Probably'? This is 'probably' the best strapline of all time, certainly up there with 'The Real Thing' in terms of memorability, and has stood the test of time through careful development ('We don't do...').

But hold on there! It now emerges that 'Probably' won't be ditched and will be used alongside the global strapline, in the UK anyway. This is a good thing 'That calls for a Carlsberg' is not even very good. It feels derivative (remember 'It's Miller time', 'If you're drinking Bacardi?' and 'Have you got a wkd side'?)

As the press office scrabbled to correct us all (the entire national media had evidently misunderstood), it serves as a reminder not only of the risks involved in 'slogalisation'. Think global, maybe, but slogans must feel relevant at a local level.

With less fanfare Heineken was this week promoting its new global strapline 'Open Your World', which could just as easily refer to a telecoms or airline brand as a beer.

Some straplines have to change. One thinks of health claims such as 'Guinness is Good for You'. Or 'Refreshing the Parts'. Or the old 'Mars a day'. In other cases it's not just the strapline that needs changing, it's the strategy. The M&S 'This is not just food' strapline was so parodied it had lost all value; while the M&S offer itself no longer felt unique.

It's addressed this brilliantly in the last year, and the results are plain to see, with like-for-like sales up 3.4% this week. Congratulations. 

Editor's Note: It is a pleasure and a privilege to edit The Grocer but in the conclusion to my leader last week, I seriously overstepped the mark.

What was meant to be a play on words was, in hindsight, clearly offensive and a major error of judgement. I apologise sincerely to Philip Clarke, Tesco and all readers of The Grocer for any offence caused.