A law protecting the word 'Anzac' from inappropriate commercial use was breached by Channel Nine on Tuesday when Today used it as the code word in a cash giveaway.

Audiences may enter the daily $10,000 "Mega-Cash-A-Roo" giveaway by texting a code word advertised by Today during the previous day's show. On Tuesday, for the Wednesday cash giveaway, that code word was 'Anzac'.

Channel Nine's Today show is facing a possible fine for breaching regulations on commercial use of the word 'Anzac'.

Under the Protection of Word Anzac Regulations, the word Anzac – or any word resembling it – in connection with "any trade, business, calling or profession or in connection with any entertainment or any lottery or art union or as the name or part of a name of any private residence, boat, vehicle of charitable or other institution, or other institution, or any building" is not permitted without the authority of the Minister for Veterans' Affairs.

Commonly approved commercial uses of the word 'Anzac' include the sale of biscuits, providing they conform to the traditional recipe and shape, and are called 'biscuits' or 'slice' rather than the Americanised 'cookie'.