Yes. Here's an example:

create table UCustomer (
person_id NUMERIC(18,0) not null,
name VARCHAR(80) not null,
salesperson NUMERIC(18,0),
primary key (person_id),
unique (name)
);

create table UEmployee (
person_id NUMERIC(18,0) not null,
name VARCHAR(80) not null,
primary key (person_id),
unique (name)
);


alter table UCustomer 
add constraint FK62B4BF5398311FBC 
foreign key (salesperson) 
references UEmployee;


When the SQL above is executed, in addition to Ucustomer and UEmployee, the table UCUSTOMER_0 is also created as a side-effect of creating the constraint. Dropping the constraint doesn't remove that table and so if you were to  drop both UCustomer and 
UEmployee and re-execute the above SQL, you would see an error like this when adding the constraint:
 *** Failure 5303 Error table 'DMR.UCustomer_0' already exists.