Unicode Explained

values, objects, events, event handlers, XML tags, HTML tags, macros, the con-

tents of files, and the output from commands.

Constant width bold

Shows commands or other text that should be typed literally by the user.

Constant width italic

Shows text that should be replaced with user-supplied values or by values deter-

mined by context.

This icon signifies a tip, suggestion, or general note.

This icon indicates a warning or caution.

The following special notations are used in this book to refer to characters:

“x”

Refers to character x by showing it within double quotation marks. For clarity,

characters that might be confused with other characters in the text—i.e., letters a–

z, A–Z, and some common punctuation, such as hyphens (-), commas (,), and

periods (.)—are enclosed in quotation marks.

U+nnnn

Refers to a character (or a code point) by its Unicode number. The number nnnn is

written in hexadecimal notation, usually in four digits using leading zeros if needed.

Web sites and pages are mentioned in this book to help the reader locate online infor-

mation that might be useful. Normally both the address (URL) and the name (title,

heading) of a page are mentioned. Some addresses are relatively complicated, but you

can probably locate the pages easily by using your favorite search engine to find a page

by its name, typically by typing it inside quotation marks. This may also help if the page

cannot be ...