Java > Core SWING advanced programming > Preface > Conventions Used in This Book
Courier font is used to indicate Java code, both in the listings and in the shorter code extracts that you'll find included in the text. The same font is also used to indicate key words and class names (such as JFrame). In some cases, we show a code extract and then explain how to modify it to change its behavior. In this case, the code that is added or modified is shown in a bold courier font.
The following icon is used to call out material that is of significance and that the reader should be alerted to:
Core Note
This icon flags information that deserves special attention, such as an interesting fact about the topic at hand, or that the reader may want to keep in mind while programming. These callouts are called Core Notes. It also may flag information that, while useful, may cause unexpected results or serious frustrations. These are called Core Alerts. And, finally, this icon also flags particularly useful information that will save the reader time, highlight a valuable programming tip, or offer specific advice on increasing productivity. These are refered to as Core Tips.