Attribute mapping rules follow a specific syntax. The syntax is
name defines an arbitrary name for the mapping rule;
soc defines the object class of the source object;
toc defines the object class of the target object;
sa defines the Lightweight Directory Access Protocol (LDAP) name of the source attribute;
ta defines the LDAP name of the target attribute;
prefix defines a prefix to the source attribute;
syntax defines the mapping syntax; and
flag defines the behavior of the mapping rule.
In most cases, the syntax definitions are intuitive, but let's look at a few of the constructs.
Source and target object classes. If no source or target object classes are defined, the mapping rule applies to all objects that the connection agreement (CA) processes (e.g., mailboxes, custom recipients, and distribution lists—DLs—from Exchange Server 5.5; mail-enabled user objects, contacts, and groups from Active Directory—AD).
You can make mapping rules more specific by specifying the entire object class hierarchy to which you want the mapping rule to apply. For example, the Active Directory Connector (ADC) applies the following mapping rule only when you're mapping an Exchange Server 5.5 DL to an AD group:
Prefix. A prefix lets you insert a fixed text string into the target attribute. You could use some text such as External, for example, to modify the distinguished names (DNs) of users in AD who are contract employees. Don't use quotation marks around the text string, and write all characters in this field directly into the target attribute.
Syntax. In most cases, you can leave the Syntax construct blank, but if the attribute you're mapping is a DN, you must specify the value DN in this part of the mapping rule. For example, in Rule 1, the attribute I'm mapping (physicalDeliveryOfficeName) has the syntax DirectoryString. (You can see the object's syntax in the Syntax text box in ADSI Edit.)
However, the following mapping rule (let's call it Rule 3)
local#organizationalPerson$person$top#user_ $organizationalperson$person$top#Manager_ #Manager##DN#2#
defines a mapping for the Manager attribute, which is a DN. Accordingly, you must set the syntax to DN on the rule.
Mapping-rule flags. A mapping-rule flag is a hexadecimal number that defines some specific behavior of the individual mapping. You can combine flags to provide composite functionality. For example, the 0x140 flag causes the behavior associated with both the 0x100 flag and the 0x40 flag. Table A describes flag-mapping behavior.