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I think you are referring to what I call a "cropped corner".
A photo of one that I have done is in this thread.
Three Completions!!!
Is this what you are meaning?
When a quilt is on the bed, the corner drapes, so that it hangs lower than the sides and end.
With a cropped corner, it evens it up more so.
That's one advantage of a cropped corner .... another being a unique design option.
I don't think of a cropped corner as an 80s thing, as
SewBizGirl mentioned.
I see it as a personal choice, when it worked for a specific quilt such as the one in this link.