A sign in the toilet block at the Lake Hume dam wall. Warning. Asbestos containing material existing in this building. Consult asbestos register prior to commencing work

A sign in the toilet block at  the Lake Hume dam wall in December 2018. Warning. Asbestos containing material existing in this building. Consult asbestos register prior to commencing work

Warning electric fence at the Divine llama Vineyard in North Carolina, USA

Warning electric fence at the Divine llama Vineyard in North Carolina, USA, in March 2020

Warning for cyclists to cross the tram tracks for the new light rail at 90 degrees, in Sydney, NSW

Warning for cyclists to cross the tram tracks for the new light rail at 90 degrees, in Sydney, NSW in January 2020

Watch out for your children around the water sign by Phalanchai Lake in Roi Et, Thailand

Watch out for your children around the water sign by Phalanchai Lake in Roi Et, Thailand in November 2019

Beware of large falling pine cones sign by giant Bunya pine trees in Bright, Victoria

Beware of large falling pine cones sign by giant Bunya pine trees in Bright, Victoria in May 2018

A vicious dog lives here in Hamilton Valley, Albury. NSW

A vicious dog lives here in Hamilton Valley, Albury. NSW in March 2018

Beware of the dog signs on a fence of a house in Hamilton Valley, Albury, NSW

Beware of the dog signs on a fence of a house in Hamilton Valley, Albury, NSW in February 2018

Cockatoo sitting on a danger do not go near the edge sign at Coogee Beach in Sydney

Cockatoo sitting on a danger do not go near the edge sign at Coogee Beach in Sydney in January 2015

Tourist without a shirt or helmet on a motorbike on a busy road at Karon Beach, Phuket, Thailand

Tourist without a shirt or helmet on a motorbike on a busy road at Karon Beach, Phuket, Thailand in August 2017

Never mind the dog, beware of owner sign in Randwick, Sydney, NSW

Never mind the dog, beware of owner sign in Randwick, Sydney, NSW in July 2017

A No swimming, crocodile sign at Gold Creek, Canberra

A No swimming, crocodile sign at Gold Creek, Canberra in July 2014

Sign at the Shakadang Trail at the Toroko national park, Taiwan. Watch your head! Be careful not to bump your head!

Sign at  the  Shakadang Trail at the Toroko national park, Taiwan in August 2010. Watch your head! Be careful not to bump your head!

No entry, warning attack dogs on patrol sign in Natal, South Africa

No entry, warning attack dogs on patrol sign in Natal, South Africa in January 2015

Painted sign on a raid showing a bicycle and car colliding in Fukuoka, Japan

Painted sign on a raid showing a bicycle and car colliding in Fukuoka, Japan in March 2015

Sign warning please drive slowly penguins in roadway at Table Mountain National Park outside Cape Town, South Africa

Sign warning please drive slowly penguins in roadway at Table Mountain National Park outside Cape Town, South Africa in January 2015

T-shirt for sale in a Thai grocery store in Richmond, Melbourne, Victoria. A woman giving a man a blow job and the slogan warning: Choking hazard for woman

T-shirt for sale in a Thai grocery store  in Richmond,  Melbourne, Victoria in April 2017. A woman giving a man a blow job and the slogan warning: Choking hazard for woman

Sign at a petrol station outside Johannesburg , South Africa. Please double check your vehicle is locked

Sign at a petrol station outside Johannesburg , South Africa in February 2015. Please double check your vehicle is locked

Wulf alarms sign in Clarens, South Africa

Wulf alarms sign in Clarens, South Africa in February 2015

Sign in a shop in Abbotsford, Melbourne. Stealing is an offence. Why risk getting court? Very clever

Sign in a shop in Abbotsford, Melbourne in March 2016. Stealing is an offence. Why risk getting court? Very clever

Sign at the Boulders, Table Mountain National Park, Cape Town, South Africa. Warning. Please look under your vehicle for penguins

Sign at the Boulders, Table Mountain National Park, Cape Town, South Africa in February 2015. Warning. Please look under your vehicle for penguins