Step 1 : Introduction to the question "4. To what does the Aussie term 'hard Yakka' refer?"
...1. A type of crusty bread 2. A semi-precious stone 3. A vehicle 4. Difficult and/or tough work Yakka is an Australian indigenous word, from the Jagera language, for work. It was adopted as a brand name for work clothing that became renowned for its durability. An advertising slogan for Yakka clothing is "Nothing's Tougher!". A television ad showed people doing sweaty, tough tasks while the accompanying jingle just repeated the phrase "hard yakka" sung in a grunting manner. Yakka clothing became a must-have for the Aussie blue-collar worker, and the term has become synonymous with demanding, laborious tasks.