Unit pricing -- offering price information based on consistent units, such as per 100gm -- has been compulsory since last December. The ACCC says that most larger supermarkets have adopted the regime well, but there's room for improvement with online stores and some smaller supermarkets.
We already know that unit pricing systems aren't necessarily consistent within the same store. The ACCC's investigation into how well it has been implemented, based on a sample of 383 stores and 17 sites, found that while large supermarkets had 98% compliance, online stores only averaged 35% (which means that there's at around dozen sites not doing the right thing). Stores that continue to ignore the code are likely to be hit with fines.
Encountered your own example of non-existent or confusing unit pricing information? Share it in the comments.