Call the LINE command, click to start. Enter a distance eg 500. The virtual line appears, 500 units long, and stays that long regardless of where you move the pointer to finally click to place it. (or you can just press enter at anytime to set the endpoint direction), but the length is always 500 units.
The point is that the length can’t be overridden by clicking.
The same applies to drawing a 2 POINT CIRCLE, or an ELLIPSE BY CENTER ie the radius or diameter can’t be overridden if it has been set numerically.
However, if a 2 Point Arc is drawn, the same does not apply. If you click anywhere within the area defined by the numerically specified arc, ie less than the radius, the click will overwrite the unit setting and the arc radius will be defined by the click relative to the starting point.
Basically, if you go to the trouble of setting the numerical constraint, you obviously want that to be active throughout the command, and allowing a random click to override it means you end up with inaccurate results…
I see this has been the case since at least V5, but it’s causing me a little bit of grief, since I expect it to behave as its cousins above, and I would therefore request that this behavior be altered to follow the same rules as similar commands.