Nuclear orientation of ^188-189Ir and ^189-191Pt

^188-189Ir and ^189-191Pt have been oriented at low temperature in the hyperfine magnetic field in iron. Precise energy measurements of some high-energy gamma rays in the disintegration of ¹⁸⁸Ir have also been performed, resulting in the modification of the high-energy level scheme of ¹⁸⁸Os. In the daughter nuclei spins and parities of excited states and multipole mixing ratios of transitions are established. For some non-unique electron-capture transitions j_beta =0/j_beta =1 intensity ratios are also deduced. Results are analysed in terms of mixed p_3/2 and f_5/2 configurations in the neutron shell.