Web Design in a Nutshell, 3rd Edition

Character References

HTML and XHTML documents use the standard ASCII character set (these are the characters you see printed on the keys of your keyboard). To represent characters that fall outside the ASCII range, you must refer to the character by using a character reference. This is known as escaping the character.

Declaring Encoding in Style Sheets

It is also possible to declare the encoding of an external style sheet by including a statement at the beginning of the .css document (it must be the first thing in the file):

@charset "utf-8";

It is important to do this if your style sheet includes non-ASCII characters in property values such as quotation characters used in generated content, font names, and so on.

In HTML and XML documents, some ASCII characters that you intend to be rendered in the browser as part of the text content must be escaped in order not to be interpreted as code by the user agent. For example, the less-than symbol (<) must be escaped in order not to be mistaken as the beginning of an element start tag. Other characters that must be escaped are the greater-than symbol (>), ampersand (&), single quote ('), and double quotation marks (“). In XML documents, all ampersands must be escaped or they won’t validate.

There are two types of character references: Numeric Character References (NCR) and character entities.