Parsed Character Data (PCDATA) is a data definition that originated in Standard Generalized Markup Language (SGML), and is used also in Extensible Markup Language (XML) Document Type Definition (DTD) to designate mixed content XML elements.
#PCDATA in XML DTD
In XML DTD, #PCDATA is the keyword to specify mixed content, meaning an element may contain character data as well as child elements in arbitrary order and number of occurrences. For example:
<!ELEMENT b (#PCDATA)> <!ELEMENT p (#PCDATA|a|b)*>
In this code, element <b> must contain character data only; element <p> can contain a mixture of any combination of character data , <a> , <b> element(s).
Although its name and its appearance in DTD suggest so, #PCDATA itself is not a semantic term for character data; it can only appear as the leading syntactic construct in mixed content definitions. The following usages are improper:
<! -- illegal usages --> <!ELEMENT p (a|#PCDATA|b)* -- use it in the middle -- > <!ELEMENT p (#PCDATA,a) -- use it in sequence -- > <!ATTLIST p title PCDATA -- use it in attribute type-->