Style guidelines are precise directions for how language should be used and are an important tool for writers. Famous examples of style guidelines include the Chicago Manual of Style and the Associated Press Stylebook, but individual companies, institutions, and organizations also have their own style guidelines. Style guidelines are extremely important because they lay out the desired format for a piece of written communication. By following style guidelines, the writer will produce a polished, professional piece of writing which meets the requirements of the organization the writer is working for.

Commonly, style guidelines include grammar conventions. This is especially important with languages like English, in which several grammatical forms are technically correct. By indicating how things such as quotes and citations should be written, style guidelines ensure consistency. For example, the wiseGEEK style guidelines clearly dictate how measurements, dates, and numbers in wiseGEEK articles should be presented. A good style guide will also indicate how things should be spelled, and which regional dialect is appropriate for the writing. For example, many American style guidelines indicate that American spellings should be used for words like color, theater, and recognize, rather than the British spellings, which are unfamiliar and confusing for American readers.

Usually, style guidelines also dictate the overall tone and content of a work as well. The level of formality required in a piece of writing is indicated in style guidelines, which will also indicate whether or not profanity and controversial topics are acceptable. Tone requirements vary widely not only from industry to industry, but also within a field, as a comparison of the style guides for the New York Times and Washington Post will reveal. Each organization has developed its own style guidelines which contribute to the unique style of the newspaper, and readers have come to expect pieces which conform to these style guidelines. Copy editors are responsible for ensuring that authors stay within the style guidelines.

For professionalism, style guidelines are crucial. In newspapers, encyclopedias, dictionaries, and other documents which require contributions from large numbers of writers, style guidelines keep the work consistent, so that readers are not jarred by personal stylistic choices which may vary. In the academic world, style guidelines help to enforce clear discipline, and also allow students to show that they can follow directions clearly. While style guidelines may seem onerous at times, following dictated style guidelines as a writer will impress your audience, and can make the difference between success and failure as a writer.