<Tr> <Th> Frequency </Th> <Th> Wavelength </Th> <Th> Designation </Th> <Th> Abbreviation </Th> <Th> IEEE bands </Th> </Tr> <Tr> <Td> 3--30 Hz </Td> <Td> 10--10 km </Td> <Td> Extremely low frequency </Td> <Td> ELF </Td> <Td> - </Td> </Tr> <Tr> <Td> 30--300 Hz </Td> <Td> 10--10 km </Td> <Td> Super low frequency </Td> <Td> SLF </Td> <Td> - </Td> </Tr> <Tr> <Td> 300--3000 Hz </Td> <Td> 10--100 km </Td> <Td> Ultra low frequency </Td> <Td> ULF </Td> <Td> - </Td> </Tr>

The absorption of rf energy is referred to as