The following signs shall not be registered as trademarks:
(1) those only relating to generic names, designs or model of the goods in respect of which the trademark is used;
(2) those only having direct reference to the quality, main raw materials, function, use, weight, quantity or other features of' the goods in respect of which the trademark is used;
(3) those lacking distinctiveness.
Any signs as listed in the proceeding paragraph acquiring distinctiveness through use and becoming distinguishable, may be approved and registered as a trademark.