In some cases a Product, Service, or Resource entity may play the role of a Configuration Specification as shown in the following Figure.<br/>The entity’s attributes (with the entity playing the role of a Configuration Specification) are used to set the values for other entities. In this case, the attributes can be “discovered” by code. If they have a value, it is used to set the value for another entity of the same type. One restriction applies here, i.e., attributes of an entity (playing the role of a Configuration Specification) must be able to be set to null (if not needed for a given situation) even if the attribute value is normally required to be set in the entity (when the entity is not playing the role of a Configuration Specification). This approach (of allowing entities to play the role of a Configuration Specification) is needed to avoid turning fixed (intrinsic) attributes of an entity into flexible, dynamic characteristics. <br/>