Description

A description is any Item from which CRISTAL can instantiate something. The core description is the ItemDescription, which is an Item that can instantiate other Items. Any Item can potentially be an ItemDescription, as they all contain CreateItemFromDescription, one of the PredefinedSteps. But in practice this will fail unless certain data is present in the Item, such as a PropertyDescription outcome.

Items that store and version definitions of C2KLocalObjects are also known as descriptions, though can be referred to as 'Definitions' to contrast with the Item description. Examples of this in the kernel are ElementaryActivityDescriptions, CompositeActivityDescriptions, and OutcomeDescriptions. Scripts do not produce C2KLocalObjects, but they are considered part of this group because they contribute to the functionality to the activity descriptions.