As I understand it the old definition which I don't believe has ever been rigid is 1:1 or greater on the sensor or film but just how many macro lenses go past 1:1? Bit thin on the ground.so in real terms it has never been a sensible description. Then there are macro zooms etc that don't even get to 1;1. All it really means going on these is a closer than normal focus. Most macro lenses too really. A typical scale might go from 1:1 to 5:1.
Maybe a better definition would be larger than life size in it's final form - hopefully showing more detail than can be seen by eye. That aspect is more important in my opinion than anything else. Perhaps people should forget the term macro photography and use photomicrogaphy instead producing micrographs and maybe also call ordinary shots macrographs
On the other hand maybe the best thing is to forget it all and wonder why the topic turned up here.
John
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