As its name reveals, XML (Extensible Markup Language) is designed as a mark-up language and not as a data object representation model. For this purpose, there are other options as JSON or YAML that are better suited.
There is a really good explanation about that in @Daniel Earwicker answer in thit topic: what is the difference between json and xml.
However, XML flexibility has made people to use a lot XML as a data object representation model.
My question is, is there any XML namespace which purpose is precisely that? Or which is the most suited? If exists, that namespace surely would intentionally limit XML flexibility. Maybe not allowing attributes or multi-layering, I don't know. Maybe the one is SOAP namespace? But it goes further because its web service protocol data. I'm too ignorant but maybe an equivalent question would be if it exists any standard xml namespace for serialization.