ASX asked ISX about Visa on 7th May 2020. Nobody knew that was happening until ISX made the public statement on 24 May 2020 that it was happening...... so it was no longer confidential.
I would say that VERY VERY few of the letters that come out of ASX are ever made public. So the public rarely knows who has been asked what, and that is how it should be. Most companies seem to prefer those enquiries remaining confidential.
ISX Price at posting:
$1.07 Sentiment: None Disclosure: Held