特別保存刀剣 Tokubetsu Hozon Touken / Special Preservation Sword

What is Tokubetsu Hozon Touken in Japanese Katana terminology?

This refers to a sword that has been appraised by the Japanese Art Sword Preservation Association and recognized as superior among the preserved swords, with good preservation condition and excellent craftsmanship. However, items that detract from the aesthetic value are excluded.