Distinguished Names

The LDAP API references an LDAP object by its distinguished name (DN). A DN is a sequence of relative distinguished names (RDN) connected by commas.

An RDN is an attribute with an associated value in the form attribute=value; normally expressed in a UTF-8 string format. The following table lists typical RDN attribute types.

String Attribute type
DC domainComponent
CN commonName
OU organizationalUnitName
O organizationName
STREET streetAddress
L localityName
ST stateOrProvinceName
C countryName
UID userid

The following are examples of distinguished names.

CN=Jeff Smith,OU=Sales,DC=Fabrikam,DC=COM
CN=Karen Berge,CN=admin,DC=corp,DC=Fabrikam,DC=COM

The following table lists reserved characters that cannot be used in an attribute value without being escaped.


See the guidance below the table about using the escape character with these reserved characters.

Reserved character Description Hex value
space or # character at the beginning of a string
space character at the end of a string
, comma
+ plus sign
" double quote
\ backslash
< left angle bracket
> right angle bracket
; semicolon
LF line feed
CR carriage return
= equals sign
/ forwards slash

If a reserved character is part of an attribute value, it must be escaped by prefixing it with a backslash (\) in the attribute string. If an attribute value contains other reserved characters, such as the equals sign (=) or non-printable characters, it must be encoded in hexadecimal by replacing the character with a backslash followed by two hex digits.

The following are examples of some distinguished names that include escaped characters. The first example is an organizational unit name with an embedded comma; the second example is a value containing a carriage return.

CN=Litware,OU=Docs\, Adatum,DC=Fabrikam,DC=COM
CN=Before\0DAfter,OU=Test,DC=North America,DC=Fabrikam,DC=COM


For more information about using distinguished names via the ADSI LDAP provider, see LDAP ADsPath.

RFC 2253