Examples of flares. The light curves are binned with 500 s time bins in one short-term exposure window; the vertical axis shows background-subtracted count rate. Upper-left: Example of a bright flare: this detection is marked in the 3XMM-DR4 catalog as obs.id. 0604820301, src. 1. It is located at the BMU pixel X = 45, Y = 16. Upper-right: Example of a flare not fully covered by observations. This detection is marked in the 3XMM-DR4 catalog as: obs.id. 0134531601,src. 2. It is located at the BMU pixel X = 45, Y = 15. Bottom-left: Example of an uncertain flare. It shows exponential decay only, which could be the decaying part of the flare. This detection is marked in the 3XMM-DR4 catalog as: obs.id. 0302970201, src. 2. It is located at the BMU pixel X = 45, Y = 14. Bottom-right: Example of a nonflare. It shows a flickering behavior. This detection is marked in the 3XMM-DR4 catalog as: obs.id. 0302340101, src. 1. It is located at the BMU pixel X = 39, Y = 19.