My question includes several point of a domain. 

In the basic setting configuration / company / report configuration is defined RML configuration for documents produced by the backoffice (well I think). 

It turns out that to produce documents on a V8 Qweb view is used! 

In the case of this validation test is used for both front office (website) in backoffice. 

Finally this is what I see in my installation. 

A rai say I do not understand this architecture if someone could have a clear explanation would be good time for everyone.