Learning > presentation > content Edit this page Content-related Rules There are 2 primary concepts for creating content: rules and specifications. Rules Define if specific set of specifications should be used to create content for specific instances: ContentRule is a container for specifications that produce content. ContentModifier is a container for modifiers that are applied to all content produced by content rules and specifications. Specifications Define what content is returned. There are 3 types of specifications: SelectedNodeInstances ContentInstancesOfSpecificClasses ContentRelatedInstances Multiple specifications can contribute to the same content rule if: There are multiple of them specified in a single rule There are multiple rules whose condition returns true Modifiers Content modifiers allow modifying content by hiding or showing properties, including additional ones, or specifying custom renderers and editors. CalculatedProperties RelatedProperties PropertyCategory PropertyOverrides Modifiers can be specified as part of content specifications or content modifiers. Last Updated: 15 June, 2021