Directory data is represented as attribute-value pairs. Any specific piece of information is associated with a descriptive attribute.
Each attribute has a corresponding syntax definition. The syntax definition describes the type of information provided by the attribute.
Table A–1 Syntax Types| 
 Syntax Method  | 
 Abbreviation  | 
 Definition  | 
|---|---|---|
| 
 Binary  | 
 bin  | 
 Attribute values are binary  | 
| 
 Boolean  | 
 boolean  | 
 Two values possible: Yes or No, True or False, On or Off  | 
| 
 Case Exact String  | 
 ces  | 
 Values are case sensitive  | 
| 
 Case Ignore String  | 
 cis  | 
 Values are not case sensitive  | 
| 
 Telephone  | 
 tel  | 
 Telephone numbers (identical to cis, but blanks and dashes (-) are ignored  | 
| 
 Distinguished Name  | 
 dn  | 
 Indicates values are DN's  | 
| 
 Integer  | 
 int  | 
 Values are numbers  | 
| 
 Operational  | 
 operational  | 
 Not displayed in search results  | 
Required and allowed attributes for each object class are included in the object class listing.
Unless otherwise noted, attributes are assumed to be multi-valued, that is, more than one instance of the attribute can be specified. Attributes that are single-valued, that is, only one instance of the attribute can be specified, are noted as such in the Syntax heading, found in each attribute definition.