Leading and next to leading large $n_f$ terms in the cusp anomalous dimension and the quark-antiquark potential

I discuss 3 related quantities: the cusp anomalous dimension, the HQET heavy-quark field anomalous dimension, and the quark-antiquark potential. Leading large $n_f$ terms can be calculated to all orders in ${\alpha }_s$. Next to leading terms with the abelian color structure $C_F^2$ also can be found to all orders (but not non-abelian $C_F{C}_A$ terms). This talk is based on Appendices C and D in [arXiv:1510.07803].