Names in a NS can be organised as one or more inverted tree hierarchies (see the left-most two NSs of Figure 7). A managed resource instance that contains another one is referred to as the superior (parent), whereas the contained managed resource instance is referred to as the subordinate (child).
FMC NM involves a federation of models, which are designed and maintained by different SDOs or standard organizations including expert groups technology-domain-specific-models. The model(s) contain classes of managed resources. Each instance has a name.
From the perspective of FMC NM, the FMC NS is partitioned into various (sub) NSs. Each (sub) NS is a collection of names of instances, whose classes are defined by the corresponding technology-domain-specific-model.
For illustration, suppose the following Figure 8 shows the (sub) NSs for names of instances whose classes are defined by, say 3GPP/SA5  (the one on the left) and MEF  (the one on the right of the figure).
This document does not specify the following, since they are specified already by specifications of various technology-domain-specific-models:
The method by which the names within a (sub) NS can be made unique;
This document specifies the method by which names among all (sub) NSs of the FNIM can be made unique.
The following procedural steps apply for operators involved:
Register itself with a domain name (e.g. "acme.com") with a domain name registrar that is accredited by the Internet Corporation for Assigned Names and Numbers (ICANN), the organization charged with overseeing the name and number systems of the Internet.
For each (sub) NS it manages, construct a naming-path using the two domain components (dc=acme, dc=com) from its registered domain name.
The name-path may contain just the two domain components from its registered domain name. It may also contain more domain components such as organization units, e.g. (dc=FixedNetwork, dc=acme, dc=com; dc=mobileNetwork, dc=acme, dc=com) or localities, e.g. (dc=montreal, dc=acme, dc=com; dc=Sorrento, dc=acme, dc=com).
Use name-path as the root of its (sub) NSs.
The following Figure 9 illustrates the use of two name-paths, where one has three and the other has two domain components, as the name-paths for the two (sub) NSs.