The element <contextRules> contains rules that can be related to one or more Schema contexts (ie, rules regarding the use of elements in various Schemas).The element can be repeated to give rules that are specific to different Schemas, where the Schema concerned is identified by the attribute rulesContext. If the attribute is not specified the contained rules will commonly apply to all objects, regardless of Schema.Rules given for a specific Schema override rules applicable to all Schema contexts. Rules specific to a Schema must be true restrictions to commonly applicable rules.