Is OneToMany UNI with JoinColumn possible?

Question

I have the following OneToMany UNI mapping with JoinColumn:

But in JPA wikibooks I read this is wrong and in case of JoinColumn an inverse relationship is required. I can't understand why. My code works. Where's the catch?

If the OneToMany uses a foreign key in the target object's table JPA requires that the
relationship be bi-directional (inverse ManyToOne relationship must be defined 
in the target object), and the source object must use the mappedBy 
attribute to define the mapping.

Answer 1

@JoinColumn on @OneToMany was introduce in JPA 2.0 before this was not possible.

Performance tip:

According to the Hibernate commiter Vlad Mihalcea it's better to use a bi-directional realtionship: https://vladmihalcea.com/the-best-way-to-map-a-onetomany-association-with-jpa-and-hibernate/