Typographical conventions

The book tries to keep a consistent style in its use of special or technical terms. Words with a special meaning to C, such as reserved words or the names of library functions, are printed in a different typeface. Examples are int and printf. Terms used by the book that have a meaning not to C but in the Standard or the text of the book, are bold if they have not been introduced recently. They are not bold everywhere, because that rapidly annoys the reader. As you have noticed, italics are also used for emphasis from time to time, and to introduce loosely defined terms. Whether or not the name of a function, keyword or so on starts with a capital letter, it is nonetheless capitalized when it appears at the start of a sentence; this is one problem where either solution (capitalize or not) is unsatisfactory. Occasionally quote marks are used around ‘special terms’ if there is a danger of them being understood in their normal English meaning because of surrounding context. Anything else is at the whim of the authors, or simply by accident.