Interface Summary
Interface	Description
OrdinalPolicy	A policy for adding category parent ordinals to the list of ordinals that are encoded for a given document.
PathPolicy	Determines which `categories` should be added as terms to the `DrillDownStream`.

Class Summary
Class	Description
NonTopLevelOrdinalPolicy	Filter out any "top level" category ordinals.
NonTopLevelPathPolicy	This class filters our the ROOT category, and it's direct descendants.

Package org.apache.lucene.facet.index.categorypolicy Description

Policies for indexing categories

There are two kinds of policies:

Path policies are based on the path of the category.
Ordinal policies are based on the ordinal of the category.

Policies are "consulted" with during indexing, for deciding whether a category should be added to the index or not. The two kinds of policies can be used for different purposes. For example, path policies dictates which categories can participate in a drill-down operation, while ordinal policies affect which can be accumulated (e.g. counted).