!!! Overview
An entry is the structure that holds information in a directory server.  It consists of the following components:
*A [DN] that uniquely identifies the entry among all other entries in the server.
*A collection of [object class|Definition -- Object Class] values that are used to govern the contents of the entry.
*A collection of [attributes|Attribute] values that contain the actual data for the entry.

Every entry is characterized by precisely one structural object class superclass chain which has a single structural object class as the most subordinate object class.

The Collection of [object classes] determines the available [attributes|Attribute] for the entry.
 
The Collection of [object class|Definition -- Object Class] determines define a set of required attributes, which must be present in the entry, and possibly [OPTIONAL] [attributeTypes], which may be included in the entry but are not required.

!! Structure of an [{$pagename}] ([RFC 4512])
An [{$pagename}] consists of a set of [AttributeTypes] that hold information about the object that the [{$pagename}] represents.  Some [attributeType] represent user information and are called [user attributes|userApplications].  Other attributes represent operational and/or administrative information and are called [operational attributes].

An [attributeType] is an attribute description with 0 or more [Attribute Options] with one or more associated values.  An [attributeType] is often referred to by its attribute description.  For example, the '[givenName]' [attributeType] is the attribute that consists of the attribute description '[givenName]' (the '[givenName]' attribute type [RFC 4519] and zero [Attribute Options]) and one or more associated values.

The [attributeType] governs whether the attribute can have multiple values, the [LDAPSyntaxes] and [matching Rules] used to construct and compare values of that attribute, and other functions.  [Attribute Options] indicate subtypes and other functions.

Attribute values conform to the defined [LDAPSyntaxes] of the attribute type.

No two values of an [attributeType] may be equivalent.  Two values are considered equivalent if and only if they would match according to the [EQUALITY] [matching Rule] of the [attributeType].  Or, if the [attributeType] is defined with no [EQUALITY] [matching Rule], two values are equivalent if and only if they are identical.  (See [RFC 4512] 2.5.1 for other restrictions.)

For example, a '[givenName]' [attributeType] can have more than one value, they must be [Directory Strings], and they are [case-insensitive].  A '[givenName]' [attributeType] cannot hold both "John" and "JOHN", as these  are equivalent values per the [equality matching rule|EQUALITY] of the attribute type.

Additionally, no attribute is to have a value that is not equivalent to itself.  For example, the 'givenName' attribute cannot have as a value a directory string that includes the REPLACEMENT CHARACTER (U+FFFD) code point, as matching involving that directory string is Undefined per this attribute's equality matching rule.

When an [attributeType] is used for naming of the entry, one and only one value of the attribute is used in forming the [Relative Distinguished Name]. This value is known as a [Distinguished Value].


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