In which Generation are the parents purebred hybrid?

In genetics, the term "purebred hybrid" can be a bit contradictory, as "purebred" refers to organisms with a consistent genetic lineage, while "hybrid" denotes a cross between different breeds or species. However, if we consider "hybrid" to mean the offspring resulting from the mating of two different purebred parents, then the parents would be considered F1 generation hybrids. Therefore, the generation of the parents themselves would be classified as the F0 generation, as they are the original purebred lines before any hybridization occurs.