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

Enterprise Root and Files

A file namespace can be named relative to

Files named relative to the enterprise root are the same as files named relative to the top organizational unit. A file context is named by using the namespace identifiers fs or _fs, relative to the organization, site, user, or host with which it is associated. For example, if orgunit/accountspayable.finance names an organizational unit, then the name user/jsmith/fs/report96.doc names her file report96.doc. The file service of the user defaults to her home directory, as specified in the NIS+ passwd table. (See File Namespace for more information on the user namespace.)

There can be no other type of context subordinate to a file system.