In contrast to the TCSEC's precisely defined hierarchy of six evaluation classes—the highest of which, A1, is featurally identical to B3, differing only in documentation standards—the more recently introduced Common Criteria (CC)—which derive from a blend of more or less technically mature standards from various NATO countries—provide a more tenuous spectrum of seven "evaluation classes" that intermix features and assurances in an arguably non-hierarchical manner and lack the philosophic precision and mathematical stricture of the TCSEC. In particular, the CC tolerate very loose identification of the "target of evaluation" (TOE) and support—even encourage—an inter-mixture of security requirements culled from a variety of predefined "protection profiles." While a strong case can be made that even the more seemingly arbitrary components of the TCSEC contribute to a "chain of evidence" that a fielded system properly enforces its advertised security policy, not even the highest (E7) level of the CC can truly provide analogous consistency and stricture of evidentiary reasoning.