For Skyline D:
Let's suppose that 'Life Ahead', which is a business run by Dulcie Smith as a sole trader, defaults upon a payment to someone. That person must know who to commence legal proceeding against. ('Life Ahead' can't be sued because it's not a legal entity, in the way that a limited company is. The action must be brought against Dulcie Smith).
For that reason, the law requires that Dulcie Smith must include her name "in legible characters on all business letters, written orders for goods or services to be supplied to the business, invoices and receipts issued in the course of the business and written demands for payment of debts arising in the course of the business".
Business Names Act 1985:
http://www.statutelaw...670913&filesize=44233
Chris