- Some use cases require the client to generate the stanza ID. In this case, the client MUST use 'client-id' as attribute name for the ID. + Some use cases require the client to generate the stanza ID. In this case, the client MUST use the 'client-id' element.
- The server MAY add an 'id' attribute to the stanza-id element. In that case, it MUST preserve the content of the 'client-id' attribute. + The server or component MAY add a stanza-id element. In that case, it MUST preserve the content of the 'client-id' element.