|For Standard||EID v4.0|
This refers to the authority portion of an Energistics URI. Conceptually, its purpose is to identify an authoritative source for information about an Energistics URI. Although this value may look like a host name and may indeed be a host name, there is no assumption or requirement that it is an actual host or the address of an actual Web service of any sort or that it can be directly de-referenced as a Web address. In general, assume that either configuration files or a discovery Web service would provide mapping between a named authority and other service endpoints.
If an authority is present, it must begin with the character sequence “//” and is separated from the rest of the hierarchy part by a single “/”. It is possible for an Energistics URI to have no authority part at all. If all cooperating services understood the meanings of the identifiers being passed, identifiers without authorities should work well within a single installation. For example, a simple sensor might use a system of local, un-qualified names for each measurement channel, such as Temperature, Pressure, etc. as its URIs, with no reference to a global authority.
It is recommended, but not required, that you use the general host/subnet naming conventions of the DNS to identify authorities with increasing universality. For example, for a WITSML store:
As with any URI, the authority is not case sensitive.