Configuring a minimum or maximum number of values for a field
The Design tab of a Schema lets you specify if a field can have a single value or multiple values. But by editing the Schema source, you can also specify a minimum and/or maximum allowed number of values.
Procedure
Results
minOccurs, and no more values than specified in maxOccurs. For example, a Component link field with its minOccurs set to 3 and its maxOccurs set to 5 means that an item based on this Schema can only be saved if it contains 3, 4 or 5 Component links.
Note that the Schema's Design tab does not show Allow multiple values as selected for this field, even though the field does allow multiple values. Also, any change to the field sets the minimum and maximum values back to their original values.