Well the threshold I would like to use is "abbreviations that are easily understood outside of coding jargon are acceptable". You don't have to be a specialist in any specific language to understand "AI" in the wild, or "NASA" or even the names of languagues such as COBOL.

But if outside of the context of coding you just say "strcpy" or "writeln" at somebody they're not going to immediately understand. As a result, even coders with tired brains or who are switching between languages a lot will also get hung up at inconvenient times.