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Another major change for ONIX 3.0’s digital support is that the <EpubUsageConstraint> composite exists at both the Product level and within the Price level. The former is used for constraints that apply at the ISBN level: constraints that apply to any product sold under the ISBN, while the latter handles the scenarios where the ISBN has different options for rental, subscription, licensing, and so on. At the Price level the constraints would be the ones at the Product level plus any constraint that applies to the specific option specified by the Price. (Note: additional considerations are needed when providing these composites but that is out of scope at this time.)