The (c) is represented as © decimal value and © hexadecimal value in XML.

<?xml version="1.0" encoding="UTF-8"?>

DTD

<!DOCTYPE Base[

    <!ELEMENT Base (second)>  

    <!ELEMENT second (#PCDATA)>

    <!ENTITY less "&lt;">

    <!ENTITY copy "&#169;">

]>

XML

<Base>

    <second>Salary is is &less; than 10K. The &copy; of the book is usually held with author.</second>

</Base>

Output

            The © of the book is usually held with author.