Can I ommit the multiplixity and role name in writing coding

If I understand you correctly, then the answer is no, you do not have to include them but you'd be making a big mistake if you omitted them.

Let us consider people. Specifically, relationships between people. There can be zero or one spouse, two parents and as many children as you like / can afford. Who would you code this? If the multiplicity can be greater than 1 it must be either an array or a collection of some sort. otherwise each role can be filled by a simple reference variable:

public class Person {
    /** The spouse of this person */
    private Person spouse;
    /** The mother of this person */
    private Person mother;
    /** The father of this person */
    private Person father;
    /** The children of this person */
    private List<Person> children;
}

Note how the role leads into the member variable name. It doesn't have to, you could have hatstand instead of children; the variable would work just as well; but it isn't easy reading it to know what it does.