In titles of books we often use a special type of language called block language. We also use block language in other discourse functions such as labels, titles, newspaper headlines, headings, notices, and advertisements. These messages are usually not sentences but consist of a noun, noun phrase, or nominal clause. We rarely need verbs and words that have low-information value, such as the articles, so these are often omitted. Not all book titles omit the article, but it is commonly done.