# Which side should the “hat” of unit vectors point to?

I'm not sure whether to post this here or on TeX.SE. If it belongs there, please move it.

When working with unit vectors in physics class, we usually write them with an upside down hat, like this: $\check{\imath}\, \check{\jmath} \,\check{\rho}$. But when looking online, I usually found them written like this: $\hat{\imath}\, \hat{\jmath} \,\hat{\rho}$. Is there a correct way to do it, or is it just convention?

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