Platform SDK: Exchange Server

The Heuristics Property

To determine the meaning of the Heuristics property and its implications for the attribute it applies to, you can examine its bits. They are interpreted as follows:

Bit Bit value and significance
0 0: Replicate the attribute between sites.

1: Do not replicate the attribute between sites.

1 0: The attribute is not accessible by anonymous clients through LDAP.

1: The attribute is accessible to both anonymous and authenticated LDAP clients.

2 0: The attribute is not accessible by authenticated clients through LDAP.

1: The attribute is accessible to authenticated clients but not to anonymous clients.

3 0: The attribute is not an operational attribute.

1: The attribute is an operational attribute.

4 0: The attribute is not visible through the Microsoft Exchange Server Administrator program, on the Attributes property page of the DS Site Configuration object. (Administrators can use this page to configure the nonoperational attributes of the site.)

1: The attribute is visible through the Microsoft Exchange Server Administrator program, on the Attributes property page of the DS Site Configuration object.


Using the Heuristics Property

By taking note of the Heuristics property, you can determine the visibility of particular attributes. For example, a Heuristics value of 3 (bit 0 = 1 AND bit 1 = 1) means that the attribute is visible by anonymous LDAP clients but is not replicated between sites.

A Heuristics value of 11 (bit 3 = 1 AND bit 1 = 1 AND bit 0 = 1) means that the attribute is an operational attribute, it is visible to authenticated LDAP clients, and it is not replicated between sites.

Note  If both bit 1 = 1 and bit 2 = 1, the attribute is accessible to authenticated clients but not to anonymous clients.

Operational attributes (attributes with a Heuristics bit 3 set) are not visible through ADSI (though they are visible through ADO) even though it is possible to set their values through ADSI. To obtain the value of an operational attribute, use an ADO query as described in the example under ADSI and ADO Samples.

Caution  Changing bit 0 of the Heuristics property could cause directory replication to stop. You should not change this bit of the Heuristics property of an attribute.