# Document Content Types Define document types. ## Discussion You specify one of the NSXMLDocumentContentKind constants in [`documentContentKind`](/documentation/Foundation/XMLDocument/documentContentKind) to indicate the kind of content required for document output. ## Topics ### Constants [`case xml`](/documentation/Foundation/XMLDocument/ContentKind/xml) The default type of document content type, which is XML. [`case xhtml`](/documentation/Foundation/XMLDocument/ContentKind/xhtml) The document output is XHTML. [`case html`](/documentation/Foundation/XMLDocument/ContentKind/html) Outputs empty tags in HTML without a close tag, such as `
`. [`case text`](/documentation/Foundation/XMLDocument/ContentKind/text) Outputs the string value of the document by extracting the string values from all text nodes. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)