2.2.8 Printer Configuration Notification Formats
This section specifies the data formats for notifications associated with the notification type identifier value AsyncPrintNotificationType_PrinterConfiguration (see section 2.2.1). The data formats are specified by using a combination of text and XML schema syntax (see [W3C-XSD]).
The XML schema document for printer bidirectional notifications MUST specify a targetNamespace attribute value of "http://schemas.microsoft.com/windows/2005/03/printing/bidi" and also MUST use that URI as the schema document's default namespace ([XMLNS] sections 2.1 and 3.0).
Print servers can use the printer configuration notification type to update clients when the printer configuration changes. Clients MUST use the unidirectional communication mode for this notification type.
The XML data contained within printer configuration notifications MUST conform to the syntax of well-formed XML 1.0 documents ([XML1.0] section 2.1). Furthermore, those documents MUST be encoded in UTF-16LE ([RFC2781] section 4.2).
Note that XML 1.0 [XML1.0], restricts the set of legal characters that can be used. Values that cannot be expressed in XML MUST NOT be represented in an XML document contained within an AsyncUI notification or response. Furthermore, some legal characters, such as "<" and "&", require some form of escaping when encoded in XML. Implementations MUST use an XML-defined mechanism, such as CDATA ([XML1.0] sections 2.4 and 2.7) or numeric character references ([XML1.0] section 4.1), to encode such characters within XML documents.