[3] PROPPATCH / PROPFIND
(RFC 4316 >>4)
は
xsi:type 属性を使います。
[1] RFC 5323 - Web Distributed Authoring and Versioning (WebDAV) SEARCH () https://tools.ietf.org/html/rfc5323#section-5.11
[2] RFC 5323 - Web Distributed Authoring and Versioning (WebDAV) SEARCH () https://tools.ietf.org/html/rfc5323#section-5.19.3