Both sides of the FK are important,
the owning side can generate a toOne (ManyToOne or OneToOne), we call this side foreignKeyToOne
the inverse side can generate a OneToMany OR a OneToOne (in case we have a pure bidirectional OneToOne, we call this side foreignKeyToInverse
Based on info from http://dev.mysql.com/doc/refman/5.0/en/show-table-status.html
Should work on pre-mysql 5 too since it uses the "old" SHOW TABLE command instead of SELECT from infotable.