Abstract To describe an individual earthquake or the seismicity of a region, simple parameters such as magnitudes are necessary. In seismicity studies observations for as long as possible time intervals should be at disposal and subsequently the continuity of the parameters' quality should be guaranteed. M GR or M S can be such parameters. m b (sp) of USGS and ISC is another one, but it has been accumulated only since the 1960s. An international proposal to introduce or revive classical m b asks to change the traditional procedure of measuring the P maximum within a few seconds from the P onset. Some confusion appears to exist for recent m b -data in EDR of USGS. It is strongly hoped that the traditional procedure of USGS for m b (sp)-determination will not be discontinued and that the new m b will be introduced only as an additional parameter.