There are two types of Restrictions: Universal quantification constraint and existential quantification constraint.
Universal quantification constraint
A universal quantification constraint is created from redefining an existing property created in the context of the owning class. This interpretation is based on {redefines} in UML, which allows for more specific constraints to be added to an existing property without defining a new one.
Existential quantification constraint
An existential quantification constraint is created from subsetting a property without giving the new property a different name (or leaving off the new property name altogether). As {subsets} with an omitted name is not well defined in UML, it is used in the Concept Modeling profile to express that a subset of values must meet the stated cardinality and type constraints of the subsetting property.