A Constraint controls the input value of a property. Constraints can be used to validate input values, and to ensure the use of certain predefined values for the properties. Constraints are defined separately from content types and aspects, and are referenced within a property type definition.
Alfresco provides four types of constraints out of the box, as follows. Apart from these four, the custom constraints can be defined by using Java Programming Language.
REGEX: ensures that a property value matches a defined regular expression pattern
LIST: ensures that a property value is picked up from a list of predefined values
MINMAX: ensures that the given property value falls within a defined numeric range
LENGTH: ensures that ...