The Code Outline window shows the structure of the text of the focused code editor. For C and C++ documents the top level symbols and types are displayed, for XML documents the nodes are displayed. For C and C++ documents the Preview tab can display documentation on the top level symbols and types. The defacto standard doxygen commands are supported for example:

/**
 * \brief Convert a given full parsed comment to an XML document.
 *
 * A Relax NG schema for the XML can be found in comment-xml-schema.rng file
 * inside clang source tree.
 *
 * \param Comment a \c CXComment_FullComment AST node.
 *
 * \returns string containing an XML document.
 */
CINDEX_LINKAGE CXString clang_FullComment_getAsXML(CXComment Comment);