1范围1。1 ISO/IEC 9594的这一部分定义了许多选定的属性集和对象类，这些属性集和对象类可能在目录的一系列应用程序中都很有用。属性集的定义涉及识别它所包含的属性，并有助于对象类的定义。对象类的定义包括可选地为其分配对象标识符，并列出与该类对象相关的许多属性类型。这些定义由负责目录信息管理的管理机构使用。 1.2任何管理机构都可以出于任何目的定义自己的对象类或子类。注（1）这些定义可能使用也可能不使用ISO/IEC 9594-2中规定的符号。（2） 建议在语义适合应用程序时，优先使用本文档中定义的对象类或从中派生的子类，而不是生成新的对象类。1.3管理机构可能支持部分或所有选定的对象类，也可能添加对象类。 所有管理机构应支持目录用于其自身目的的对象类（top、alias和DSA对象类）。

1Scope1.1This part of ISO/IEC 9594 defines a number of selected attribute sets and object classes which may be found useful across a range of applications of the Directory. The definition of an attribute set involves identifying the attributes that it contains, and facilitates the definition of object classes. The definition of an object class involves optionally allocating an Object Identifier to it, and listing a number of attribute types which are relevant to objects of that class. These definitions are used by the administrative authority which is responsible for the management of the Directory information.1.2Any Administrative Authority can define its own object classes or subclasses for any purpose.NOTES(1) These definitions may or may not use the notation specified in ISO/IEC 9594-2.(2) It is recommended that an object class defined in this document, or a subclass derived from one, be used in preference to the generation of a new one, whenever the semantics is appropriate for the application.1.3Administrative authorities may support some or all the selected object classes, and may also add object classes.All Administrative authorities shall support the object classes which the directory uses for its own purpose (the top, alias and DSA object classes).