Example
XML pre-defines five general entities that can be used without declaring them:
& " ' < >
They are associated with the names amp, quot, apos, lt and gt.
<?xml version="1.0"?>
<entities>
& is an ampersand.
" is a quote.
' is an apostrophe.
< is a lower-than sign.
> is a greater-than sign.
</entities>
