The letters O and A went missing from the Northern Advocate's page one masthead yesterday as part of a lifesaving bid for blood.
O and A represent the types of blood New Zealanders are being urged to donate.
The Missing Type campaign first emerged in Britain last year.
Megabrands such as McDonald's, Google, Coca-Cola and Microsoft were among global businesses which removed the letters representing blood types from their websites, Twitter handles and signage to help promote the UK National Health Service's appeal for new blood donors last year.
In Britain, type B is in demand, so the letter B was removed.
In New Zealand, types O and A are needed, so companies such as NZME - which owns the Northern Advocate and New Zealand Herald - removed those letters.
Hence the Northern Advocate's unusual masthead yesterday.
Advocate editor Craig Cooper said the paper was happy to be involved. "I can't give blood myself, because I lived in the UK in the 'mad cow years'.
"But we're happy to urge Northlanders to sign up - read Trisha Makene's experience on this page today and consider what would happen if those blood supplies were not available."
This year, the NZ Blood Service has received commitments from several brands to join the Missing Type campaign in a bid to sign up 10,000 eligible donors.
The owners of several iconic advertising installations - including the hillside "Wellington" sign above the capital's airport, the L&P bottle in Paeroa and the Ohakune carrot - had agreed to remove the letters from digital images during the campaign. But as part of the top-secret move, the brands provided no explanation until this morning, confusing many readers and consumers.
The Child Cancer Foundation wrote on its Facebook page: "Wh-t d- y-u think is g-ing -n? W-uldn't y-u like to kn-w! Watch this space to find out more #MissingType #NZBlood."
The Starship Foundation wrote: "W-uldn't y-u like t- kn-w!"
Blood Service chief executive Sam Cliffe said "Our real need is As and Os."
In New Zealand, 85 per cent of people are A or O, so their kind of blood is in greatest demand.
"We also want to look at getting young donors," Mr Cliffe said. "If we get them at high school or school-leaving age, often they stay life-long."
The number of active donors has fallen from 128,412 in the 2011 financial year to 109,158 last year, says to the service's annual report. Mr Cliffe said in part this reflected changes in the way blood products were used, but that did not eliminate the need for new donors to join up.
He said fewer whole-blood donors were needed, but rapidly rising demand for products made from plasma - a component of blood comprising mainly water, plus proteins, hormones and clotting factors - meant more plasma-only donors were needed.
To become a plasma-only donor, which carries additional eligibility criteria, new donors must first give a unit of whole blood.
Last year more than 59,000kg of plasma, up from 49,000kg in 2011, was sent to a Melbourne laboratory for processing into blood products for use in NZ.
The NZ Blood Service produced some 112,000 units of red blood cells last year, down from 138,000 in 2011.
HOW TO DONATE:
* Visit the NZ Blood Service website for a list of donor sites and to see whether you are eligible to donate: http://www.nzblood.co.nz/give-blood/where-to-donate/