I'm starting to remember some now.
If the engine automatically prefixes, then how does the user overrides the prefix? With an OGM specific annotation?

@Entity class User {
    @Embedded
    @Nested(name="h_address")
    Address homeAddress;
}

@Embeddable class Address {
    @Column String zipCode;
}

Other questions, if I do not want the prefix, i.e. don't want to store it nested, how do I do it? @Nested(doNotNest=true) or @DoNotNest?

These seem today useless for Infinispan, EhCache and Cassandra but useful for the others (document store + graph).

We could then have the persister / tuple constructor prefix accordingly.

An orthogonal idea is to have the tuple key offer a path object rather than this dot base separation in a string.