Stephen Woodford, Chief executive, DDB UK
To rename something suggests owner-ship: when the English conquered the Dutch territories in the US they ren-amed New Amsterdam New York.
This statement of 'co-ownership' by consumers is a brand's dream. Unpro-mp-t-ed, active engagement shows how important the brand is in people's lives.
To rename something, particularly when it makes it feel closer and friend-lier, shows real affection and implies the brand identity is so strong that the real name is unnecessary.
However, Marks & Spencer is prob-ably right not to use 'Marks & Sparks'. Instead, the brand sits astride 'Marks & Spencer' and 'M&S', retaining its pres-tige, and connection with traditional middle-class shoppers who view it as a social distinction. So the key is whether the nickname supports brand identity.
Maccy D's is affectionate and inform-al, suggesting McDonald's close relat-ion-ship with customers.
If I were Primark, I'd do the same with 'Primarni' - the nickname my teenage daughter uses that reinforces its low-budget, high-fashion status.
Christian Woolfenden, Global marketing manager, Bacardi
We hear all too often that the explosion of the digital world means consumers are more in control of brands than ever.
The reality is they've always been in control. Everything we do is based on their needs and wants. That doesn't mean I ask them to redesign the packaging, but it does mean I want to know what they think.
The same applies to slang names; often affectionate diminutives, they show the brand is deeply embedded in the cultural consciousness of everyday life. I want to understand it, but it's wrong to try to own it.
Hearing a brand referring to its own nickname makes my skin crawl, in the same way as my teachers trying to be 'cool'. It's a boundary that shouldn't be crossed and brands need to be careful about the same (over)familiarity.
The Kentucky Fried Chicken switch to KFC was an intelligent repositioning exercise, taking the brand beyond fried chicken. Registering 'Maccy D's' will be about future libel cases vs consumer communication. As brand custodians we should probably leave it there.
Don Williams, Chief executive, pi global
Great brands aren't products - they're personalities and, just like any personal-ity, they become part of our lives for better or worse.
Is it any surprise that consumers (and, of course, the press) create nick-names for them such as Macca for Paul McCartney and Becks for David Beckham?
The best brand names are short and punchy. Coca-Cola has four syllables and Coke has one. The two live happily side by side, the Coca-Cola script act-ing as an iconic visual mnemonic for the brand, and Coke providing a con-sumer-friendly verbal branding.
Everyone reading this probably has a nickname, abbreviation or derivation. Usually these names are affectionate, but occasionally they're not.
If anything these names demonstrate inherent brand strength through famil-iarity. After all, I'm writing this on my Mac, not an Apple Macintosh.
Alex Marks, head of business marketing, Ebay
While it got McDonald's some good headlines I think the idea of somehow trademarking 'slang' is misguided.
Slang, by its definition, is deliberately used for effect and it is very much owned by the consumer.
Once a corporation starts to try to take it back, it loses its power and could then become redundant.
Brands should be happy they are well regarded and familiar enough to have their own slang and leave it at that.
The other issue is locality. Cultures have their own slang, it is not a global thing, so trying to enforce it on a market will just not work.
This is even the case with something as ubiquitous as the mobile phone. In the US it's 'cell phone', in the UK it's 'mobile'. In Germany? 'Handy'.