About Character References

Characters not found in the normal alphanumeric character set, such as < and &, must be specified using Numeric Character References or predefined Character Entities. This process is known as escaping the character.

A Numeric Character Reference (NCR) refers to a character by its Unicode code point in either decimal or hexadecimal form. Decimal character references use the syntax &#nnnn;. Hexadecimal values are indicated by an “x”: &#xhhhh;. For example, the less-than (<) character could be identified as &#60; (decimal) or &#x3C (hexadecimal).

Character entities are abbreviated names for characters, such as &lt; for the less-than symbol. Character entities are predefined in the HTML and XHTML DTDs as a convenience because they may be easier to remember.