The organizational unit namespace provides a hierarchical namespace for naming subunits of an enterprise. Each organizational unit name is bound to an organizational unit context that represents the organizational unit. Organization unit names are identified by the prefixes org/, orgunit/, or _orgunit/. (The shorthand alias org/ is only used in the initial context, never in the middle of a compound name. See "Initial Context Bindings for Naming Within the Enterprise" and "Composite Name Examples".)
In an NIS+ environment, organizational units correspond to NIS+ domains and subdomains.
Under NIS+, organization units must map to domains and subdomains. You must have an organizational unit for each NIS+ domain and subdomain. You cannot have "logical" organization units within a domain or subdomain. In other words, you cannot divide an NIS+ domain or subdomain into smaller organization units. Thus, if you have a NIS+ domain doc.com. and two subdomains sales.doc.com. and manf.doc.com., you must have three FNS organizational units corresponding to those three domains.
Organizational units are named using dot-separated right-to-left compound names, where each atomic element names an organizational unit within a larger unit. For example, the name org/sales.doc.com. names an organizational unit sales within a larger unit named doc.com. In this example, sales is an NIS+ subdomain of doc.com.
Organizational unit names can be either fully qualified NIS+ domain names or relatively named NIS+ names. Fully qualified names have a terminal dot; relative names do not. Thus, if a terminal dot is present in the organization name, the name is treated as a fully qualified NIS+ domain name. If there is no terminal dot, the organization name is resolved relative to the top of the organizational hierarchy. For example, orgunit/west.sales.doc.com. is a fully qualified name identifying the west organization unit, and _orgunit/west.sales is a relatively qualified name identifying the same subdomain.
In a NIS environment there is only one organization unit per enterprise which corresponds to the NIS domain. This orgunit is named orgunit/domainname where domainname is the name of the NIS domain. For example, if the NIS domain name is doc.com, the organizational unit is org/doc.com.
In an NIS environment, you can use an empty string as a shorthand for the organizational unit. Thus, org// is equivalent to org/domainname.
There is only one FNS organization unit and no subunits when your primary enterprise-level name service is files-based. The only permitted organization unit under files-based naming is org//.