Tobacco package warning messages are warning messages that appear on the packaging of cigarettes and other tobacco products concerning their health effects. They have been implemented in an effort to enhance the public's awareness of the harmful effects of smoking. In general, warnings used in different countries try to emphasize the same messages. Warnings for some countries are listed below. Such warnings have been required in tobacco advertising for many years, with the earliest mandatory warning labels implemented in Iceland in 1969. Implementing tobacco warning labels has been strongly opposed by the tobacco industry, most notably in Australia following the implementation of plain packaging laws.