Our new Arena is meant to have no sponsor signs, so what's this? Perth Arena under construction in 2012. Perth architect Dominic Snellgrove says the symbol (not pictured), which appears to be the number seven when viewed from some angles, is actually the letter Z. Picture: Theo Fakos A SECRET deal, a coincidence, or one of the best guerilla-style advertising campaigns ever pulled off in Perth? That's what patrons are trying to decide after spotting what appears to be a close replica of a Channel 7 logo emblazoned on the side of Perth Arena in Northbridge. Sports Minister Terry Waldron has ruled out selling sponsorship or naming rights for the venue. But the land on which it was built was sold to the State Government by Kerry Stokes' former Seven Group, now Seven West Media, fuelling speculation the TV network may have got a signage sweetener for offloading the property. Channel 7 said last night there was no sponsorship deal and it had nothing to do with the design on the outside of the building. Mr Waldron also ruled out a sponsorship arrangement, secret or otherwise, and said the architects for the project came up with the design. One of the men who helped, Perth architect Dominic Snellgrove, said the symbol appeared to be the number seven when viewed from some angles, but it was actually the letter Z. It is one of four giant 3D letters Z, Y, X and T that are spaced around the exterior walls of the Arena, spelling the ancient and now obsolete Kentish word "Zyxt," which means "to see." "It's been mistaken for a seven . . . but it's actually not," Mr Snellgrove said. Zyxt is the final word in the long version of the Oxford Dictionary which in old English means 'to see', so it's a reference to the spectacle and the act of going and participating and seeing a show at the Arena. People are always very interested in understanding the layers of meaning in the building. Back when it was still being built, one of the project managers asked us if it was a seven, but the answer is, 'No, definitely not'. Despite no formal sponsorship deal, the likeness of the Z to the Channel 7 logo could still be reaping some dividends for the network, according to John Driscoll, chief executive of Perth advertising agency Marketforce. From an angle where you don't see the bottom bit of the logo, yes, it's a seven. Does it look like the Channel 7 logo? No, because it's not the way they do their logo and it's not red," he said. But people will read this story and have their own discussions. It will almost be one of those urban myths. In this instance, it's not close enough to generate that guerilla-tactic-type reaction. But now that you've pointed it out to me, I will see a seven every time I drive past it. Other people probably will, too. It is not the first time sponsorship rights have caused a controversy in WA. In 2010, naming rights to rebadge Subiaco Oval as Patersons Stadium were sold to financial company Patersons Securities for $3.5 million, and last year Premier Colin Barnett said he would not sell naming rights to Perth's new sports stadium being built in Burswood. University of WA marketing expert Jamie Murphy said naming rights often came down to simple economics. "The sceptic in me thinks that nothing is sacred, and that the almighty dollar will win out in the long run," Prof Murphy said.