Creating Directories
By creating directories, you make it possible to replicate and manage groups of object entries according to where, how often, or by whom they are used. Grouping related object entries into separate directories also makes it easier to control access because it allows you to take advantage of default ACL entry propagation.
CDS cell configuration creates an initial hierarchy of directories under the root so that DCE components can fix locations within the namespace where they can create and catalog their object entries. Among the directories created by cell configuration is the subsys directory, beneath which Independent Software Vendors (ISVs) can create their own directories to store the object entries that are used by their distributed applications.
Alternatively, ISVs and other users of the namespace may prefer to create a hierarchy of directories of their own design under the root to store their information.
(See OSF DCE Administration Guide - Introduction for more information on the initial hierarchy that is established by cell configuration.)
More:
Permissions for Creating a Directory
Entering the directory create Command
Checking the ACL Entries for a New Directory
Upgrading the Directory Version on the Cell Root Directory
Upgrading the Directory Version on a Directory