XHTML Document Type

The Extensible HyperText Markup Language (XHTML), is a markup language that has the same depth of expression as HTML, but also conforms to XML syntax.

A file is considered to be an XHTML document when the root element name is html.

Default schemas that are used if one is not detected in the XHTML file are stored in the following locations:
  • XHTML 1.0 - [OXYGEN_INSTALL_DIR]/frameworks/xhtml/dtd/ or [OXYGEN_INSTALL_DIR]/frameworks/xhtml/nvdl/.
  • XHTML 1.1 - [OXYGEN_INSTALL_DIR]/frameworks/xhtml11/dtd/ or [OXYGEN_INSTALL_DIR]/frameworks/xhtml11/schema/.
  • XHTML 5 - [OXYGEN_INSTALL_DIR]/frameworks/xhtml/xhtml5 (epub3)/.

The CSS options for the XHTML document type are set to merge the CSS stylesheets specified in the document with the CSS stylesheets defined in the XHTML document type.

The default CSS files used for rendering XHTML content in Author mode are stored in [OXYGEN_INSTALL_DIR]/frameworks/xhtml/css/.

The default catalogs for the XHTML document type are as follows:
  • [OXYGEN_INSTALL_DIR]/frameworks/xhtml/dtd/xhtmlcatalog.xml
  • [OXYGEN_INSTALL_DIR]/frameworks/relaxng/catalog.xml
  • [OXYGEN_INSTALL_DIR]/frameworks/nvdl/catalog.xml
  • [OXYGEN_INSTALL_DIR]/frameworks/xhtml11/dtd/xhtmlcatalog.xml
  • [OXYGEN_INSTALL_DIR]/frameworks/xhtml11/schema/xhtmlcatalog.xml
  • [OXYGEN_INSTALL_DIR]/xhtml5 (epub3)/catalog-compat.xml