Every attribute defined in the server's schema has a syntax associated with it. The syntax defines the kind of information that is expected to be held in the attribute so that the server can perform the appropriate kinds of matching against it. The syntax definition also allows the server to properly index the values so that searches against it can be processed quickly.
Directory Server Enterprise Edition introduces a configurable option, check-syntax-enabled, set by using the dsconf command, to ensure that updated attributes adhere to the syntax definitions. Attribute values are rejected when they violate the syntax definitions. For example, when syntax checking is on, if a user tries to update an attribute with an integer syntax to include a non-numeric value, the update will be rejected.
By default, syntax checking is off. When syntax checking is on, all import and update operations are checked.