As COVID-19 spreads across the nation we all know somebody who's a casual contact or have been pinged ourselves.
We now have a nationally recognised definition of a close contact and rules to follow.
But what about those who are pinged on state-based apps as visiting a site where a COVID-positive case was, a "case alert" as they are labelled on the Service NSW app - what in seemingly old terms was a "casual contact".
With PCR testing queues hours long and people being turned away; and rapid antigen tests almost impossible to source, what do you do if you're pinged as a casual contact in order to keep your friends and family safe?
The answer it seems lies now in "personal responsibility".
Last week Prime Minister Scott Morrison told reporters those who did not meet the definition of a close contact should not be in the queue for a PCR test.
"If you don't fulfil this definition of a close contact then there is no need for you to be in that line," Mr Morrison said.
"You should go home. Go to the beach, go and do what you want to do. Read a book in the park. Follow all the normal, common sense things that you would do."
The quote came as authorities desperately tried to reduce the queues at testing centres as people tried to fill requirements for travel and of course, because they had symptoms or were a close or casual contact.
A new national definition of close contact followed that only people who have been with a positive case for more than four hours in certain settings now needed to isolate. Isolation was shortened to seven days, with rapid antigen testing replacing PCR tests in some situations.
Western Australia is the sole Australian state yet to adopt the Prime Minister's definition of close contact.
WA Premier Mark McGowan said he did not expect the changes to come into effect before the state's February 5 reopening, although he said he agreed "in principle" with the new rules.
But this definition hasn't been welcomed by all health professionals.
Dr Nick Talley, Medical Journal of Australia editor-in-chief, called the revised definition "nonsense".
"Many people catch COVID from fleeting contact, bring it home, have no symptoms for the first few days, infect their family and then get ill. The reason for the changes is pragmatic; there isn't enough testing capacity despite having months to plan the reopening," he wrote in this article.
"The new policies will result in a large rise in undiagnosed cases in the community and increase spread further. It's rationing, from poor planning.
"The new policies won't protect most of us. Going forward we will be largely responsible for our own testing, contact tracing, and if sick with COVID (unless very ill) self-care."
His advice to protect yourself and your family was to buy N95/P2 masks and use them when out rather than cloth or surgical masks and to avoid crowded indoor venues.
He said everybody should have a COVID plan to self-isolate if needed.
"Consider a home oxygen monitor. HEPA filtration devices clear the air of virus. Make sure everyone in the family is fully vaccinated and get a booster as soon as you can. If you haven't a family GP, find one."
Similar reaction came from University of NSW Professor of Epidemiology, Mary-Louise McLaws, on Twitter.
She wrote in a four part tweet: "COVID infects within minutes and travels more than 1.5m, long-COVID is real and hospital numbers only part of story."
"Not providing free RATs to households only privileged and wealthy will be able to protect themselves and reduce wider risk of spread."