Each element/attribute has a cardinality indicator that specifies the number of allowable occurrences within a template instance. The cardinality indicators are interpreted with the following format "m…n" where m represents the least and n the most:
0..1 zero or one
1..1 exactly one
1..* at least one
0..* zero or more
1..n at least one and not more than n
0..0 none [SHALL NOT]