Photo: ©  2009 AP via AAP/Rick Rycroft

The Tramontana restaurant's "thongage" charge is all part of owner John Spellman's campaign to lift dress standard for his boutique eatery.

"It's a formal restaurant – tablecloths, napkins ... I wear shoes and socks," he told the Northern Territory News.

He argues that his restaurant gives Darwinians the opportunity to dress formally for a change, and diners are warned of the fee as they walk through the door via a sign.

Spellman is so adamant about the dress code that the $10 charge even has its own designated button on the cash register.

"I just put it on the bill – you don't have to argue about it.

"Two lamb chops, one thongage."