Tip of the Day: Protecting book titles

A friend asked me today about protecting a book title, and it's a good subject for a general tip. Book titles - and similar things, such as song titles - won't usually be protected by copyright. A great deal of thought might go into them, but it's not enough to make them original literary works. But the law of passing-off might give them protection, and they might be registrable as trade marks. A bit of lateral thinking might well get you the protection you hope for.
Trade marks are, however, supposed to be badges of origin, and book titles aren't. They often refer to what's in the book rather than indicating the commercial source of the book, which is usually done by identifying the publisher separately or in the name of a series, such as the Rough Guides. As trade marks, titles that describe what the book's about will be pretty useless.
With time, a descriptive trade mark can become registrable: it might also be protected under the law of passing off. Marketing activities and evidence of sales revenue will help show that the title has broken through the barrier and acquired the features of a trade mark. So too will ancillary products, commercial spinoffs, and merchandising: they might exist at a distance from the book, but they will help make the title an indication of origin. "Gone With The Wind" has been a UK registered trade mark since 1993, "The No 1 Ladies detective Agency" since 2004, though that title could be considered to have attached itself to a series of novels.