BA offered 10% discount of the fare element of any flight only online purchase to be flown on BA metal (not codeshares) to shareholders in BAY.L
You had to own 200 BA shares on the record date, usually early November, to qualify.
You earn BA Miles, but not onbusiness points, on such fares.
This scheme is still available to existing exBAY.L shareholders now in IAG, but to my knowledge the benefit has not been confirmed to be available to those who purchase IAG shares now or in the future.
Having said that, the scheme has recently been expanded to incorporate Iberia flights, and can now be used exEUR which wasn’t the case previously and the expectation is that it will be extended to IAG shareholders for flights on both BA and IB, and I would expect an announcement to that effect this summer. No details on the amount of shares required to qualify.
Nothing certain on this, though.
Chapter and verse on this thread: