Nintendo applies for a trademark for the Triforce
The Triforce is an iconic symbol from Nintendo's Legend of Zelda series. It's been used in games, toys, clothes, and to decorate some of Nintendo's limited edition handheld systems. So it would make sense that Nintendo would want ensure their ownership of it, and as of now, they certainly are trying to. The company registered a trademark for usage of the word Triforce in all gaming media (mobile, handheld, and console games). It's interesting to note that Nintendo of America has had a trademark on the name since 2011, but Nintendo of Japan has not.
Source