PCDATA

PCDATA stands for parsed character data. In SGML and XML, PCDATA is a content model token used in DTDs to indicate that an element’s content consists of text that should be parsed by the processor. This means that character references and entity references within the text are expanded, and the text is not treated as literal markup.

PCDATA can appear in two main forms in a DTD. The simplest form is a pure textual element, such as <!ELEMENT title (#PCDATA)>, where the element may contain only parsed text. A more flexible form is mixed content, where text may appear alongside certain child elements, for example <!ELEMENT paragraph MIXED (#PCDATA | bold | italic)*>. In a MIXED model, the parser allows text interspersed with the specified child elements.

A key limitation is that an element declared with a content model of (#PCDATA) alone is not allowed to contain nested elements. If an element needs to include both text and child elements, a MIXED content model or a more expressive schema (beyond DTDs) is required.

CDAT A, a related concept, refers to sections of text that are not parsed for entities or markup. In XML, CDATA sections are used to include literal text that may contain characters that would otherwise be treated as markup, whereas PCDATA is always parsed.

Examples: a title element with text only, or a paragraph that contains both text and inline elements like emphasis. PCDATA remains a foundational concept in DTD-based validation, differentiating parsed textual content from literal, non-parsed data.