XML predefines the following internal entities:
&
gives you the ampersand character (&
),
which cannot be used because it is used for introducing
internal entities.
<
gives you the "less than" character (<
),
which otherwise introduces tags.
>
gives you the "greater than" character (>
),
which otherwise termiantes tags.
"
gives you the double quote ("
).
'
gives you the single quote (apostrophy, '
).
These two are especially useful when you have to use quotes in the value of an
attribute.
&#xxx;
, which xxx
being a decimal number,
gives you a 16-bit ISO/IEC 10646 character. This is also called a "character reference".
You can define your own internal entities
in the document header.