Plain-language answer: 2G ALE commonly refers to the second-generation system standardized in MIL-STD-188-141A and related specifications using an 8-ary FSK waveform and structured words.
Why it matters
It is widely interoperable and supported by many HF radios, but scan rates, addresses, channel lists, and optional functions must match.
Put it into practice
Build and version-control a shared fill, verify time and scan settings, test individual and net calls, and record LQA before deployment.
The common mistake
Calling two radios 2G-compatible without testing the same programmed network.
System boundary
Current channel authorization, waveform specifications, radio and tuner manuals, electrical code, exact antenna configuration, and tested interoperability control. A stored match or automation result does not prove radiated efficiency or network readiness.
