In classification , one of the distinguishing characteristic s of a class , identified as a means of differentiating it from other classes. As defined in FRBR ( Functional Requirements for Bibliographic Records ), one of a set of characteristics enabling users of information to formulate queries and evaluate responses when search ing for information about a specific entity . Attributes can be inherent in the entity (physical characteristics, labeling information, etc.) or supplied by an external agent (assigned identifiers, context ual information, etc.). For example, the logical attributes of a creative work include its title , form, date of creation, intended audience , etc. As a general rule, a given instance of an entity exhibits a single value for each attribute, but multiple values are possible (a work may be published under more than one title or in more than one form), or a value may change over time ( date of publication for serial s).