Reduced nonlocal matrix integrable modified Korteweg–de Vries (mKdV) hierarchies are presented via taking two transpose-type group reductions in the Ablowitz–Kaup–Newell–Segur (AKNS) spectral problems. One reduction is local, which replaces parameter ? with its complex conjugate ??, and other one nonlocal, negative ???. Riemann–Hilbert problems thus inverse scattering transforms formulated from...