The Swift Sneak enchantment exclusively operates when applied to leggings in the legs slot

The Swift Sneak enchantment is limited to functioning solely when applied to leggings in the legs slot. This differs from the Depth Strider, Aqua Infinity, Respiration, and Feather Falling enchantments, which are compatible with any item in any armor slot. These enchantments work on all four armor pieces, elytras, pumpkins, and all types of heads/skulls, but this versatility is not extended to the Swift Sneak enchantment, which is exclusive to leggings in the leggings slot. Through the use of an anvil, players can add Soul Speed to items other than boots as intended by MC-95555. If horses were capable of sneaking, it is likely that the Swift Sneak enchantment would not function on horse armor either. It seems that enchantments introduced in version 1.9 and later are restricted to their designated items and armor slots unlike older enchantments.