The relative precedence in which classifiers are applied: higher numbers represent classifiers with higher precedence. Classifiers with the same precedence must be unambiguous i.e. they must define non-overlapping patterns, and are considered to be applied simultaneously to the traffic stream. Classifiers with different precedence may overlap in their filters: the classifier with the highest precedence that matches is taken.

On a given interface, there must be a complete classifier in place at all times for the first TCB (lowest value of diffServClassifierTcb) in the ingress direction. This means that there will always be one or more filters that match every possible pattern that could be presented in an incoming packet. There is no such requirement for subsequent TCBs in the ingress direction, nor for any TCB in the egress direction.