System Administration Guide: Naming and Directory Services (DNS, NIS, and LDAP)

Choosing Your Directory Suffix

A directory suffix is the directory entry that represents the first entry in a directory tree. You will need at least one directory suffix for the tree that will contain your enterprise's data. It is common practice to select a directory suffix that corresponds to the DNS host name used by your enterprise. For example, if your organization uses the DNS name example.com, then select a suffix of dc=example,dc=com.

For more information on planning the suffixes for your directory service, see the iPlanet Directory Server 5.1 Deployment Guide.