Labels:black | darkness OCR: Used to mark new concepts, WARNINGS, and keywords in a language. Used for emphasis in text. It is also used to indicate commands for the user to type when showing screen interaction (see below). Used to mark meta-variables in the text, especially in representations of the command line. For example, 18 -1 foo where foo would "stand for" a filename, such as /bin/cp. Used to represent screen interaction. Also used for code examples, whether it is "C" code, a shell script, or something else, and to display general files, such as configuration files. When necessary for clarity's sake, these examples or figures will be enclosed in thin boxes. Represents a key to press. You will often see it in this form: Press return to continue. A diamond in the margin, like a black diamond on a ski hill, marks "danger" or "caution." Read paragraphs marked this way carefully. This X in the margin indicates special instructions for users of the X Window System.
