Wanda mentions "low level altocumulus formations". Pretty much by definition, fluffy style cumulus clouds are low level, less than 6000 feet above ground level. But "altocumulus" means high altitude cumulus and applies to clouds from 6000 feet to about 20,000 feet AGL. A high altitude cloud at the bottom of the alto range might be called a low level altocumulus but that just tortures our language.