System Administration Guide: Naming and Directory Services (FNS and NIS+)

site

The namespace identifier site (or _site) is bound in the initial context to the root of the site naming system of the top organizational unit of the enterprise to which the host running the process belongs.

From the initial context, the names site and thisens/site resolve to the same context. For example, if the host running the process is the machine aldebaran and aldebaran is in the enterprise doc.com., the name site/pine.bldg-5 names a conference room, pine in building 5 of doc.com.