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An alias entry in an LDAP directory is an entry that points to another entry. Following an alias pointer is known as dereferencing an alias. In R5.0.9, there is a new field in Directory Assistance documents for LDAP directories called "Dereference Alias on search." This field has the following options that control searching of aliases in an LDAP directory.

Option	Description
Never	Never dereference alias entries. Choose this option to improve search performance if there are no alias entries in the directory that require dereferencing.
InSearching	Dereference alias entries subordinate to a specified search base, but do not dereference an alias search base entry.
FindingBase	Deference an alias entry for a specified search base, but do not dereference alias entries subordinate to the search base.
Always	Always dereference aliases. This selection is the default, and the behavior prior to R5.0.9. Note: the field popup help incorrectly states that the default selection is Never.

Note that dereferencing aliases by choosing InSearching, FindingBase, or Always can result in poor search performance with some LDAP directories.

Examples
Suppose:
A) an LDAP directory has the following entries:
o=Acme1
o=Acme2 (alias entry that points to o=Acme1)
cn=John Doe, o=Acme1
cn=John Doe, o=Acme2 (alias entry that points to cn=John Doe, o=Acme1)

B) Directory assistance has to process a subtree search with the base o=Acme2 (a search of o=Acme2 and its subordinate entries).

Given A) and B), the following table describes the search results each " Dereference Alias on search" option returns.

Option selected	Entries returned
Never	o=Acme2 cn=John Doe, o=Acme2
InSearching	o=Acme2 cn=John Doe, o=Acme1
FindingBase	o=Acme1 cn=John Doe, o=Acme2
Always	o=Acme1 cn=John Doe, o=Acme1