Writers have books, directors have films, even ads in their entirety can be considered pieces of work - but not the (hopefully killer) endline.
"Most advertising slogans are what one might term hackneyed expressions,
Philip Circus, the chairman of the Advertising Law Group, says. "The cleverness is not in the expression but in the use of the expression."
Circus has 25 years' experience as a member of the committee of advertising practice under his belt.
He says that because of the inherent nature of the endline, copyright laws do not easily protect it.
Very few catchphrases can be said to be original in the sense of an original form of words. So the problem with straplines is twofold. First, they are rarely original in the copyright sense. Second, they are of insufficient length to qualify as a work. Law protects original work.
A classic example of this can be seen right now as Unilever and Procter & Gamble fight it out for the right to use the words "secret", "beautiful
in straplines for products.
Recent advertising by Unilever for its Dove hair-care products used the strapline: "Secret to beautiful hair". P&G, on the other hand, used the phrase "What's the secret of beautiful hair?
in a teaser campaign for its Pantene range. P&G has reputedly threatened to take Unilever to court if the Dove ads are not pulled.
There were also concerns in January when Canon's new endline, "You can", was seen as being remarkably similar to Microsoft's "Yes, you can!" slogan.
Since 1994, the law has recognised that slogans central to a brand can be registered as a trademark. However, only a few - such as "A Mars a day helps you work, rest and play
- have been operative for long enough to qualify.
The time taken both to establish a slogan as part of a brand and to then register it as a trademark, which can take up to a year, further muddies the waters.
"I am often surprised by just how uninformed agencies are about how straplines can be protected,
Stephen Groom, a partner at Osborne Clark and a media law specialist, says. "A strapline devised for a new campaign they think is wonderful may actually be infringing on an existing trademark."
"Agencies don't do the simple things like check the UK trademark registry.
That can be done online,
Groom continues. "And, of course, the disastrous situation is that you run a wonderful strapline, then find out that someone's already got it and is threatening you with legal proceedings. It does happens a reasonable amount. A lot of the disputes will be settled confidentially.
"When they do happen, though, they cause a lot of grief for the agency. The client won't be happy, costs run up and agency insurance policies, if they have that sort of cover, get bent."
Circus says that the British Code of Advertising can come to the rescue when the courts can't. "When two companies are just smacking each other over the head, they are basically not after anything other than an institution (such as the Advertising Standards Authority) to declare that they are right and the others are wrong,
The code states that "advertisers should not make unfair use of the good will attached to the trademark, name, brand or ad campaign of any other organisation". "You can see it is easier to establish that you've used unfair use of good will than to establish copyright infringement," Circus says.
"It's a lot easier, quicker and cheaper. Going to court may take a very long time to get a judgment - ASA decisions will come within a couple of months."