Just to make it a bit easier to see:



I think we have seen this mentioned before on this forum. What what I can make out, it is offered quite rarely and selectively, and tied in with future travel. I actually think it's quite cunning in many ways. If you had been Gold a long time, and you slip a year, then they tend to be indulgent, at least the first time around. But don't kid yourself, BA only do this so you can show them some more money.....