manytomany.php

<?php
/** @Entity */
class User
{
    // ...

    /**
     * Many User have Many Phonenumbers.
     * @ManyToMany(targetEntity="Phonenumber")
     * @JoinTable(name="users_phonenumbers",
     *      joinColumns={@JoinColumn(name="user_id", referencedColumnName="id")},
     *      inverseJoinColumns={@JoinColumn(name="phonenumber_id", referencedColumnName="id", unique=true)}
     *      )
     */
    private $phonenumbers;

    public function __construct()
    {
        $this->phonenumbers = new \Doctrine\Common\Collections\ArrayCollection();
    }

    // ...
}

/** @Entity */
class Phonenumber
{
    // ...
}