Help:Cardinality

"cardinality" sensu MOD-CO schema indicates 1. the optionality and 2. the exclusivity of a descriptor/ certain concept in relation to a description of an item as defined.

1. optionality of descriptor first value: 0 (not mandatory descriptor) first value: 1 (mandatory descriptor)

2. exclusivity of descriptor second value: 1 (text descriptor, sequence descriptor, categorical descriptor if indicated as exclusive, because they occur only once for an item) second value: n (categorical descriptor if not indicated as exclusive, quantitative descriptor, because they may occur more than once for an item )

Summarizing:

- Categorical descriptors: cardinality 0..n (standard), 0..1 (exclusive), 1..n (mandatory), 1..1 (mandatory & exclusive)

- Quantitative descriptors: cardinality 0..n (standard), 1..n (mandatory)

- Text + Sequence descriptors: cardinality 0..1 (standard), 1..1 (mandatory)