Which breed is NOT classified with a semi-arch type?

The Standard Chinchilla breed is recognized for its unique conformation, which does not fit the semi-arch type classification. Instead, it is categorized as a compact or commercial type. The semi-arch type includes breeds that have a moderate arch over their body, which begins at the shoulders and smoothly transitions to the hindquarters.

Breeds like the Flemish Giant, American, and English Lop display that characteristic semi-arch in their body structure, making them suitable for classification in that category. The Standard Chinchilla, owing to its distinct body shape and proportions, stands apart from this classification, highlighting its compactness and roundedness rather than a defined arch.