Quiz Entry - updated: 2026.10.22
What do the common naming attributes dc, o, c, ou, cn and uid mean in an LDAP name?
dc = domain component, o = organisation, c = country, ou = organisational unit, cn = common name, uid = user ID; they are the attribute types used in RDNs to build the path of a DN.
| Attribute | Long name | Typical use | Example |
|---|---|---|---|
dc |
domainComponent | One label of a DNS domain, used for the root | dc=example,dc=com |
o |
organizationName | The organisation as root | o=acme |
c |
countryName | Country, as a two-letter ISO 3166 code | c=de |
ou |
organizationalUnitName | Department or container | ou=People, ou=webdesign |
cn |
commonName | Full name of a person, group or device | cn=James Bond |
uid |
userid | Login name of a user | uid=juser |
Two conventions for the root are in use. The older X.500 style names the root after the organisation (o=acme), often with a country (o=acme,c=de). The now more common style maps the company's DNS domain onto the tree (dc=acme,dc=com), which makes the root globally unique for free; Active Directory always does this.
Tip: c holds a two-letter code, not a country name: a search for (c=germany) does not match an entry with c: DE.
Go deeper:
RFC 4519: LDAP Schema for User Applications — the definitions of c, cn, dc, o, ou, uid and the other standard attributes.