The small vertical line below is supposed to be always contiguous with the base letter. The rational is that the character should be seen as one whole character rather than a base character and a modifier.

If I may reiterate the background, the vertical line was proposed as against the dot because with use, the dot wore off and disappear from the die before the base character. This was in the days of die casting. Hence, the contiguity of the small vertical line and the base character promoted longevity of the die.

Now that printing technology has changed radically, thank to ICT, the problem of the wearing dot has disappeared but few have taken notice. The under dot now seems to be tolerated because the dot does not wear.

I think the change in printing technology may instigate or ultimately force a change in the standard.