Each entry has a unique relative distinguished name (RDN), which distinguishes it from all other entries with a particular immediate superior in the DIT.
An RDN consists of one or more assertions of the type and value of an attribute. A pair consisting of an attribute type and a value of that type is known as an Attribute Value Assertion (AVA). All attribute types in an RDN must be different. The attribute value of an attribute in an RDN's AVA is called the distinguished value of that attribute, as opposed to the other possible values of that attribute.
The assertion is TRUE if the entry contains an attribute of the specified type, and if one of that attribute's values matches the AVA's distinguished attribute value. An entry commonly has an RDN that consists of a single AVA. In some cases, however, more than one AVA may be required to distinguish an entry. (See Multiple AVAs.)
The entry shown in the figure, A Directory Entry Describing Organizational Person, contains the RDN Common-Name = Alfred Schmidt. The attribute consists of two values: Alfred Schmidt and Al Schmidt. The AVA Common-Name = Alfred Schmidt contains the value Alfred Schmidt, which has been designated as the distinguished value in the AVA.