Flare ribbon location of various types of flares (standard microflares, hard microflares, and a medium-size flare) that occurred within AR12882. The orange contours represent the flare ribbons identified in the AIA 1600 Å images of the hard microflares, while the blue contours represent all other events. The intensity map from SDO/HMI is plotted in the background. The legend includes the percentage of the AIA 1600 Å contour used, the GOES class, and the electron spectral index δ. This figure clearly shows that hard microflares are rooted in sunspots (umbra or penumbra), while standard microflares, which have a soft spectrum or a total lack of nonthermal emission, are located far from sunspots.