An XML element encoded as a UTF-8 string. The possible encodings for a NodeId value. An identifier for a node in a UA server address space. An identifier for a node in a UA server address space qualified with a complete namespace string. A 32-bit status code value. A recursive structure containing diagnostic information associated with a status code. A string qualified with a namespace index. A string qualified with a namespace index. A value with an associated timestamp, and quality. A serialized object prefixed with its data type identifier. A union of several types.