!!! Overview
[{$pagename}] [SupportedControl] allows a [DUA] to request the [DSA] to return specific attributes of [Linked Attribute] entries along with the link, under the assumption that this operation can be performed by the DSA in a more efficient manner than the [DUA] would itself by performing the complete sequence of required search operations.

[{$pagename}] is defined in [Internet Draft] [{$pagename}] which expired in [2009|Year 2009]

!! 2.2 Control Request
The control type is deref-oid.  The specification of the Dereference Control request is:
{{{
controlValue ::= SEQUENCE OF derefSpec DerefSpec

DerefSpec ::= SEQUENCE {
    derefAttr       attributeDescription,    ; with DN syntax
    attributes      AttributeList }

AttributeList ::= SEQUENCE OF attr AttributeDescription
}}}

The derefAttr must be be a [DN] and of [DN Syntax] ([1.3.6.1.4.1.1466.115.121.1.12]).

Each derefSpec.derefAttr MUST be unique within controlValue.

!! 2.3.  Control Response
The control type is deref-oid.  The specification of the Dereference Control response is:
{{{controlValue ::= SEQUENCE OF derefRes DerefRes

DerefRes ::= SEQUENCE {
    derefAttr       AttributeDescription,
    derefVal        LDAPDN,
    attrVals        [0] PartialAttributeList OPTIONAL }

PartialAttributeList ::= SEQUENCE OF
                        partialAttribute PartialAttribute}}}

PartialAttribute is defined in [RFC 4511]; the definition is reported here for clarity:
{{{PartialAttribute ::= SEQUENCE {
    type       AttributeDescription,
    vals       SET OF value AttributeValue }
}}}
If partialAttribute.vals is empty, the corresponding partialAttribute is omitted.  If all partialAttribute.vals in attrVals are empty, that derefRes.attrVals is omitted.

[{$pagename}] This [LDAP] [SupportedControl] is currently implemented in OpenLDAP software using the temporary [OID] [1.3.6.1.4.1.4203.666.5.16] under OpenLDAP's experimental OID arc.

!! More Information
There might be more information for this subject on one of the following:
[{ReferringPagesPlugin before='*' after='\n' }]
----
* [#1] - [https://tools.ietf.org/html/draft-masarati-ldap-deref-00|Wikipedia:https://tools.ietf.org/html/draft-masarati-ldap-deref-00|target='_blank'] - based on information obtained 2018-10-28- 
* [#2] - [8.6. Performing Dereferencing Searches|https://access.redhat.com/documentation/en-US/Red_Hat_Directory_Server/8.2/html/Administration_Guide/dereferencing-searches.html|target='_blank'] - based on information obtained 2018-10-28-