This appears to be used for handling TEMPORARY enchants to weapons - like POISONS. Also appears to be self-only.
hasMainHandEnchant, mainHandExpiration, mainHandCharges, hasOffHandEnchant, offHandExpiration, offHandCharges, hasThrownEnchant, thrownExpiration, thrownCharges
hasMainHandEnchant = 1 (true) or nil mainHandExpiration = time remaining as thousandths of seconds mainHandCharges = charges remaining hasOffHandEnchant = 1 (true) or nil offHandExpiration = time remaining as thousandths of seconds offHandCharges = charges remaining hasThrownEnchant = 1 (true) or nil (new in 4.0.1) thrownExpiration = time remaining as thousandths of seconds (new in 4.0.1) thrownCharges = charges remaining (new in 4.0.1)
Reference the default interface BuffFrame.Lua for its usage.