In recent DIII-D (J.L. Luxon et al2003 Nucl. Fusion43 1813) experiments, suppression of type-I edge localized modes (ELMs) was obtained by applying n = 3 resonant magnetic perturbations using a single toroidal row of internal, small aperture coils located either above or below the equatorial plane in plasmas with ITER-like electron pedestal collisionality , flux surface shape and low edge safety factor (q95 ≈ 3.6). ELM suppression with a single row of coils was achieved at approximately the same q95 surface-averaged perturbation field as with two rows of coils, but required higher current per coil. Suppression of type-I ELMs was not obtained with similar n = 3 perturbation strength at the q95 surface from a single-row of external, large aperture coils on the outer equatorial midplane.