Ten Genera
All Low Clouds Cumulonimbus Cumulonimbus Cumulus Cumulus Stratus Stratus Stratocumulus Stratocumulus Medium Clouds Altostratus Altostratus Altocumulus Altocumulus Nimbostratus Nimbostratus High Clouds Cirrocumulus Cirrocumulus Cirrus Cirrus Cirrostratus Cirrostratus Special Clouds/Phenomenon Species Varieties Supplementary Features and Accessory Clouds