Yes, it has started. Ofcom announced the new rules on November 17, 2006, which will be published in March. There will be full implementation on July 1.
There'll be no what we call fat, salt, and sugar advertising in children's programs, including those for pre-school children; no HFSS advertising on dedicated children's channels; no HFSS advertising on programs of particular appeal to children under 16; no celebrities or licensed characters to be used in ads for those; and no nutritional health claims in the fat, sugar, and salt ads aimed primarily at children.
They are very specific, and Ofcom's assessment is that this package of rules will reduce children's exposure to advertising's impact by 41% for 5- to 15-year-olds and 51% for 5- to 9-year-olds. That will commence operation later this year.