Claire Harvey: If you listen carefully you'll hear the real message

Hairdryers are for drying the hair on your head ONLY. So declares a large and very bossy sign on the wall of the ladies' changing room at an inner-Auckland public swimming pool.

Next to the sign is a picture of a dark-eyed woman with long black locks that may or may not have been dried with a hairdryer.

She looks very pleasant, the lady in the sign. She looks a lot like most of the pool's patrons, actually. That is, she looks like she has Asian heritage, although the sign doesn't baldly state that she is Asian, or that doing strange things with hairdryers is a particularly Asian habit.

In today's New Zealand, you have to look for the underlying message. Just now, there seem to be quite a few underlying messages about the strange and unfamiliar habits of some people.

Like this sign, pinned up on the inside of a public-toilet door in Christchurch.

"Please do not put feet on the seats", accompanied by a picture of a large shoe, crossed out with a red line.

It's slightly baffling until you work out the real point - please don't use this as a squat toilet.

And here's another message. Don Brash declared this week, at the launch of his immigration policy titled "A Responsible Middle Course" that "we" in New Zealand don't want a certain type of immigrant - the immigrants "who come with no intention of becoming New Zealanders or adopting New Zealand values".

"We do not want those who insist on their right to spit in the street; or demand the right to practise female circumcision; or believe that New Zealand would be a better place if gays and adulterers were stoned," Brash said.

Notice he doesn't actually say that these habits are Asian, African and Islamic - although that is what we hear at a subtler level.

This is classic dogwhistling - that is, saying something which sounds quite straightforward, but which sends a very different message at a higher pitch that resonates with certain listeners, just as dogs are able to hear noises on a much higher register than humans.

Spitting in the street is a habit associated in the public mind - fairly or not - with Asians.

A Hong Kong newspaper recently railed against the tendency of mainland Chinese to expectorate when they visit the island.

Beijing residents named public spitting as their most-hated element of life in the Chinese capital, in a survey published earlier this year.

Anyone who's visited Southeast Asian countries like Thailand, or the Indian subcontinent, has seen plenty of people spitting in public.

But then so has anyone who's ever watched a game of rugby in New Zealand.

An All Black test just doesn't feel right until one of the players is caught on camera sending a mouthful of saliva on to the turf. Then he and 29 other blokes begin rolling around in it.

So is spitting actually dirty, or a cause of disease?

Not really, says Otago University epidemiologist Dr Michael Baker - although he says any person carrying a disease should try to refrain from sneezing, coughing or otherwise distributing what he delicately describes as "droplets" on the rest of us.

"If the person doesn't have an infection of the respiratory system and is spitting clean mucus, that's not going to be a risk for other people," says Baker.

"Most people don't have infectious diseases and if they're spitting, it's just a behaviour, not a risk. Phlegm is unpleasant but it isn't necessarily a source of infection."

In his Wellington office, Baker has a 1950s poster produced by the New Zealand Department of Health (as it was then known) in the campaign against tuberculosis, declaring: "Don't spit! Disgusting and Dangerous."

That must have been before the dawn of the heyday of spit-free New Zealand values that Don Brash remembers.

Tuberculosis, which can be treated with antibiotics, infects around one billion people around the world, and the latest official figures show 186 New Zealanders have been diagnosed with the respiratory condition since January 1, a rate which researchers say has been steady for the past 20 years.

But was Brash really concerned about the spread of tuberculosis when he whistled his warning on spitting? This was the launch of National's policy on immigration, remember, not health.

And let's have a look Brash's verbs. Who ever "insisted" on their right to spit in the street? Who is "demanding" the right to practise female circumcision? And shouldn't proud New Zealanders be allowed to "believe" whatever they like?

It all sounds odd from the man who claims to loathe Labour's Nanny State.

So what else is the National Party worrying about? Grammar, apparently.

Brash's speech continued: "We want immigrants who will be Chinese New Zealanders, or Pacific Island New Zealanders - not New Zealand Chinese or New Zealand Pacific Islanders."

So when new Kiwis introduce themselves (in English please) they should be careful to invoke this nation as a noun and not an adjective.

Brash had been careful earlier in his speech to stick with very simple grammar when describing his own family. "My wife was born in Singapore, as has been noted from time to time. Two of my three children were born in the United States."

We can only hope that all members of the family cover their mouths when they cough.