Naming rules of ferrite magnets

Do you know the naming rules of ferrite magnets?

Ferrite magnets have their own naming rules. Now they basically use Chinese naming rules. At first there were Fer 3 or Feroba 3, but now these hierarchical names are no longer used. Later, the initial letter "C" of the ferrite (Ceramics) is used to name the hierarchy, such as C5 and C 8. The United States and Britain still use this rule....