I understand he meant something different: that you can use Testing in two different ways: 1) by explicitly referring to "testing" in your apt configuration. T

I understand he meant something different: that you can use Testing in two different ways: 1) by explicitly referring to "testing" in your apt configuration. Then it's rolling forever. 2) by referring to the current "testing", so for example "bullseye". Then you're temporarily on testing, rolling for a while until the day bullseye becomes the new stable, and then you're on stable too. I often do this a bit ahead of a new stable on my personal laptop, to check what's coming with the new stable. I guess it's probably quite common.