SIR Peter Cosgrove has been widely acknowledged as one of most laidback Governor-Generals Australia has had. Despite that, don't be temped to slap him on the back, pat him on the shoulder or throw an arm around the former Australian defence chief if you run into him in Warwick this week.

Sir Peter is on a three-day visit of the Southern Downs and Granite Belt and will open the 150th Warwick Show on Friday night.

He will mingle with the show crowd and visit several community groups during his stay leaving some residents asking how to correctly greet him.

Sir Peter is a representative of Queen Elizabeth II and while his title comes with far less pomp and ceremony than meeting a member of the royal family, the role commands some formalities.

Sir Peter's spokesman said the GG liked people to feel relaxed in his company, but etiquette around his title dictated how people greet him at official functions.

"People usually address him as Your Excellency and then Sir Peter after that,” the spokesman said.

He suggested not to call him Governor as that is the term state and territory governors were referred to.

"There isn't any intense protocol around meeting him and anyone who goes up to Sir Peter to chat will find him very welcoming and relaxed,” the spokesman said.

A handshake was the correct way to meet and greet Sir Peter.

Show organisers have declined to comment how large Sir Peter and Lady Cosgrove's entourage will be, but it is believed they will travel with at least two officials.

Warwick Show committee chairman John Wilson said organisers applied several months ago to invite the G-G to open the show.

"The council has also invited him to the region and the timing was perfect as it was around the 150th show,” Mr Wilson said.

"I know he was very interested in being here due to show's big anniversary.”