XML : Services with shared namespace for error respons?

My goal was to build a framework for our microservices, with the tool set that we need and we are using XML as our primary format.

So my thoughts were that all microservices should have a similar error response, all services using the same namespace for the error response. Same thing with our "health check".

The goal is that the framework can handle the building of the error response all the same, without a developer having the need to customize it. Unless they need to. Which also means the client can handle errors from multiple services the same way.

Service Foo would then have for example, ErrorResponse (shared namespace with other services) and FooResponse (unique namespace for that service), FooBarResponse (same namespace as FooResponse - unique for the service)

Are there some guidelines or best practices that different services cannot share the same namespace?

Other thoughts?