0 Ω links are commonly used on SMT boards as bridges, to avoid having to either have another layer or make routing easier when you have relatively hard constrai

0 Ω links are commonly used on SMT boards as bridges, to avoid having to either have another layer or make routing easier when you have relatively hard constraints (e.g. ground planes behind antennas). The added marginal cost of a 0 Ω 0201 SMT link is basically $0 to about 3 s.f.. The added cost of another layer in the board is decidedly nonzero. Yes, they made me blink the first time I encountered them too...