This specification intends to meet the following requirements:

The keywords "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 .

This specification uses the following syntax to define normative outlines for messages:

This specification can be used in terms of XML Information Set (Infoset) , even though the specification uses XML 1.0 terminology. Valid Infoset for this specification is the one serializable in XML 1.0, hence the use of XML 1.0.

The elements defined in this specification MAY be extended at the points indicated by their outlines and schema. Implementations MAY add child elements and/or attributes at the indicated extension points but MUST NOT contradict the semantics of the parent and/or owner, respectively.

Extension elements and attributes MUST NOT use the Web Services Event Descriptions namespace URI.

An implementation is not compliant with this specification if it fails to satisfy one or more of the MUST or REQUIRED level requirements defined herein. A SOAP Node MUST NOT use the XML namespace identifier for this specification (listed in ) within SOAP Envelopes unless it is compliant with this specification.

Normative text within this specification takes precedence over the XML Schema, which in turn take precedence over outlines, which in turn take precedence over examples.

Unless otherwise noted, all IRIs are absolute IRIs and IRI comparison MUST be performed according to section 5.3.1.

Implementations are expected to support both UTF-8 and UTF-16 as described in XML 1.0.

The XML namespace URI that MUST be used by implementations of this specification is:

lists XML namespaces that are used in this specification. The choice of any namespace prefix is arbitrary and not semantically significant.

The working group intends to update the value of the Web Services Event Descriptions namespace URI each time a new version of this document is published until such time that the document reaches Candidate Recommendation status. Once it has reached Candidate Recommendation status, the working group intends to maintain the value of the Web Services Event Descriptions namespace URI that was assigned in the Candidate Recommendation unless significant changes are made that impact the implementation or break post-CR implementations of the specification. Also see http://www.w3.org/2001/tag/doc/namespaceState.html and http://www.w3.org/2005/07/13-nsuri .

A key concept in the description and advertisement of event information is the "Event Type". An Event Type is a description of the syntactic structure and value space of the set of events that share that type. Event Types are independent of the pub/sub protocol used and the format of the notifications used to transmit those events.

Event Types are described within an EventDescriptions element where they contain a complete description of an event. A key aspect of this description is the associated XML Schema Global Element Declaration (GED) for each event. EventDescriptions element has the following form:

The XML Schema for the EventDescriptions element can be found in . The following describes additional, normative constraints on the outlined listed above:

Note, while the schema allows for the @element attribute and the @actionURI attribute to be absent, at least one of them MUST be present for each eventType.

The following is an example of an EventDescriptions element that could serve as a description of the Event Type used in .

Lines (12-14) describe an Event Type with a QName of "{http://www.example.org/oceanwatch/notifications}:WindReportEvent". The GED for this Event Type is defined on line (08) as being of type "{http://www.example.org/oceanwatch}:WindReportType".

The sample EventDescriptions in might describe the following notification: