4 services carry this tag in their source record. Tags come from the provider, not from us — a tag is a claim about what the service does, not proof that it does it well.
RF band catalogue search: given a frequency or band name fragment, returns every matching band with range, region, uses and legality.
RF legality check: country + frequency (+ optional power) returns whether the band is licence-free, the power and duty-cycle limits, and the governing rule for US, EU, JP or CN.
Sub-GHz band plan by country (US, EU, JP, CN): every allocated range with service name and access conditions, as a single machine-readable table.
Sub-GHz RF band lookup: given a frequency in MHz, returns the band, region, common uses and legality notes.