ldap design

Hi, After much advice from all helpful folks here, I've managed to come out with an initial design. I can't wait to get this design finalised and start coding in PHP. 1. I'm thinking of designing my name space design as shown below. Any advice/comment is greatly appreciated. dn: dc=company, dc=com objectclass: dcobject dc: company dn: ou=departments,dc=company,dc=com objectclass: organizationalunit ou: departments dn: ou=people,dc=company,dc=com objectclass: organizationalunit ou: people dn: o=departmentName1, ou=departments,dc=company,dc=com objectclass: organization o: departmentName1 dn: o=departmentName2, ou=departments,dc=company,dc=com objectclass: organization o: departmentName2 dn: uid=username1,ou=people,dc=company,dc=com objectclass: organizationalperson objectclass: inetorgperson uid: username1 cn: username1 o: depepartmenName1 dn: uid=username2,ou=people,dc=company,dc=com objectclass: organizationalperson objectclass: inetorgperson uid: username2 cn: username2 o: depepartmenName2 2. Is sub-dividing departments and users using ou=people and ou=departments recommended and the usual practice? Can I do without it or it's better to have? 3. Is there any hierarchy between o and ou. I always thought that o should be higher hierarchy than ou (i.e dn: ou=department,o=department,dc=company,dc=com). Is this true? Any problem using "dn: ou=department,o=department,dc=company,dc=com"? What is difference for the following DNs design? Which is the recommended design pls? dn: o=departmentname, ou=departments, dc=company,dc=com or dn: ou=departmentname, o=departments, dc=company,dc=com or dn: cn=departmentname, ou=department, dc=company,dc=com or dn: cn=departmentname, o=department, dc=company,dc=com or Many thanks for your time and advice. Best Regards.