Addressable fields

Hello everyone,
In edgeX demonstration API Walk Through documentation in paragraph “Defining your Data” shows how to create the addressable that have the information about the physical device(section 5.4.2). I m not sure what is the purpose of the fields : “publisher”, “user”, “password”, topic". Is it something optional? i saw that these fields are not mentioned to the next steps (register, provisioning, client registration etc) . Can we use that fields to create some kind of tenants ?

Those are used if you’re addressing an MQTT broker or something that required authentication, but otherwise they can be left empty