Constraint in Grails

Grails use constraint key word for Domain class's constraint.As a note,I summary the constraint in Grails Domain Model.

Name	Example	Description
blank	title(blank:false)	Set to false if a string value cannot be blank
email	email(email:true)	Set to true if the value must be an email address
inList	sex(inList:['Man','Woman'])	Value must be contain within the given list
length	title(length:1..50)	Use a range value to restrict the length of string or range
min	age(min:new Date()	Set the minimun value
minLength	title(minLength:5)	Set the minimum length of a string or array property
minSize	children(minSize:10)	Set the minimum size of a collection or number property
matches	name(matches:/[a-zA-Z]/)	Matches the supplied regular expression
max	age(max:new Date()	Set the maximum value
maxLength	title(maxLength:5)	Set the maximum length of a string or array property
maxSize	children(maxSize:10)	Set the maximum size of a collection or number property
notEqual	name(notEqual:'Eric')	Must not equal the special value
nullable	name	Set to false if property value cannot be null
range	age(range:30..60)	Must occur within the special range
size	children(size:5..15)	Use a range to restrict the size of a collection or number
unique	name(unique:true)	Set to true if the property must be unique
url	url(url:true)	Set to true if a string value is a url address