30–300 Hz Super low frequency

300–3000 Hz Ultra low frequency

3–30 kHz Very low frequency

30–300 kHz Low frequency

300 kHz – 3 MHz Medium frequency

3–30 MHz High frequency

30–300 MHz Very high frequency

300 MHz – 3 GHz Ultra high frequency

3-30 GHz Super high frequency

30–300 GHz Extremely high frequency

300 GHz – 3 THz Tremendously high frequency

After Ultra High, we could have had Jumbo, Colossal, Super Colossal. and Mammoth frequency ranges.

Not to be confused with Colossal wavelengths, which is what we could have used if we need to fiddle around below Extremely Low frequencies..

[1] https://en.wikipedia.org/wiki/List_of_common_display_resolut...

Though yes in my experience, at those frequencies people stop using ITU designations, and switch to IEEE (S,C,X-band etc).