Learning > presentation > content > E C Expressions Edit this page Content-related ECExpressions Rule Condition Content rules have a condition ECExpression property which defines which rules should be applied for which instances. The following ECExpression symbols are available there: Symbol Type Value SelectedNode NavNode context Expression context of NavNode the content is being requested for. ContentDisplayType string Preferred display type of the content. It identifies which component will be used to show the content. SelectionProviderName string Name of the selection handler that last changed the selection. IsSubSelection bool Indicates whether the last selection event changed the main selection or sub selection. Additionally, Ruleset variable symbols are available as well. Instance Filter ECExpressions that are specified in instanceFilter specification properties are converted to ECSQL WHERE clause, so they have some limitations - ony a subset of all the ECExpression symbols are available. The below table lists all of them: Symbol Type Value this ECInstance context ECInstance expression context of ECInstance that's currently being handled SelectedInstanceKeys ECInstanceKey context[] A value list of primary ECInstance keys Additionally, User Setting symbols are available as well. Last Updated: 15 June, 2021