<!-- DEFINE $VALUE = 'xyz' -->
{$VALUE}
<!-- DEFINE $VALUE = 'abc' -->
{$VALUE}
<!-- IF $VALUE != 'abc' -->
$VALUE != 'abc'
<!-- ELSEIF $VALUE == 'abc' -->
$VALUE == 'abc'
<!-- ENDIF -->
<!-- INCLUDE define_include.html -->
{$INCLUDED_VALUE}
{$VALUE}
<!-- UNDEFINE $VALUE -->
{$VALUE}
<!-- DEFINE $VALUE = 'test!@#$%^&*()_-=+{}[]:;",<.>/?' -->
{$VALUE}