[SA 6] - SQL Reference for adding constraints

SQL Reference is missing the foreign key structure in adding constraints section. After entering ALTER TABLE schema.table taking the ADD Table_constraints route leaves me to choose either PRIMARY KEY or UNIQUE. I guess there should be a FOREIGN KEY (column_name) REFERENCES ( ... ) junction too, to create queries like this example in the help:

	Code:
	ALTER TABLE Person.ContactBackup ADD CONSTRAINT FK_ContactBacup_Contact FOREIGN KEY (ContactID) REFERENCES Person.Person (BusinessEntityID) ;