This article and attachment applies to versions 2014 R2 and earlier only. For the current version see Reporting References Between Items in the Custom Reporting User Guide. Also available from the Reports tab of CaseComplete.
When creating a custom report, you'll want to show items that are related to a given item, such as the requirements referenced by a use case. To do this, you nest a $repeat, $list or $table statement inside an outer $repeat, known as the context. For example, if the outer repeat was $repeatUseCases and nested within that repeat section there was a $listActors, you would be retrieving actors in the context of a use case, i.e. the list of primary and supporting actors.
The table in the attached document indicates what items will be returned when requesting a list of items in a given context. If a cell in the table is marked N/A it means the combination is not applicable, e.g. a $listActors in the context of a requirement doesn't make sense because there is no relationship between actors and requirements.