2.1 About the Conceptualization Standard

It should be noted that two different physical objects may happen to be attached to the same conceptual profile. This leads to a notion of ``conceptualization equivalence'' among objects which has to be managed by the system.

Classnames form a strict hierarchy representing the enumerative side of SOUR's classification scheme. From the user's perspective, the supremum of this hierarchy is AOG (Abstract Object Generic attributes), a class consisting mainly of system controlled attributes such as:

• name - AO name as defined by the user who created the object;
• pathname - plugging so-called PAOs (``Physical AOs'') into the underlying file system;
• insertedBy - username of user who created the object;
• lastModifyDate - date of last updating;
• lastLookDate - date of last browsing;
• nModify - number of updatings so far;
• etc.

Facets are 6-tuples of terms, each term instantiating one of the following, predefined facet types :

Every term instantiating a facet must be present in a subsystem of SOUR called LTS (Lexicon/Thesaurus Subsystem). Terms are related to each other by concepts in a fuzzy way supported by CTS (Context Thesaurus Subsystem), another component of the SOUR architecture [16][15]. Facets may be regarded as ``fuzzy'' attributes. Reference [10] provides a formal discussion about the power of fuzzy classification in practice.