The /.:/subsys entry is the directory for subsystems. Subdirectories below subsys are used to hold entries that contain location-independent information about services, particularly RPC binding information for servers.
The dce directory is created below /.:/subsys at configuration. This directory contains directories for the DCE Security Service and Directory File Service (DFS) components. The functional difference between these two directories and the fs and sec junctions described in The DFS and DCE Security Service Junctions is that the latter two entries are the access points for the components' special databases, whereas the directories under subsys/dce contain the services' binding information.
Subsystems that are added to DCE should place their system names in directories created beneath the /.:/subsys directory. Companies adding subsystems should conform to the convention of creating a unique directory below subsys by using their trademark as a directory name. Use these directories for storage of location independent information about services. You should store server entries, groups and profiles for the entire cell in the directories below subsys. For example, International Air Freight-supplied subsystems should be placed in /.:subsys/IAF.