The following is available on the Canada Border Services Agency (CBSA) website.
D10-15-28, Tariff Classification of Footwear, Covering the Ankle
This memorandum outlines the CBSA’s administrative policy with respect to the expression “footwear, covering the ankle” found in various subheadings in Chapter 64, and provides clarification with respect to the term “covering the ankle”, as found in Chapter 64 of the Customs Tariff (Tariff).
The Section and Chapter Notes offer no definition of either “covering” or “ankle”. Likewise, the relevant Explanatory Notes offer no clarification.