>> padding and margin are used to separate logically separate pieces of
>> text.
> I think those are used to separate visually, not logically.
Currently, padding and margin are indeed considered to be purely visual
separation, and that is precisely my complaint. I claim that in actual
usage, the items they separate are logically independent items and need
logical separation, not just visual separation.
> Why should positive paddings / margins be treated differently
from negative or
> zero-width ones?
Well, zero margin is the default, and certainly can't be indicate a logical
separation of the element. I am not sufficiently versed on the usage of
negative margins to claim anything one way or the other. In any case, that
was fantasai's original proposal.
> BTW anyway, same rules should apply to Hebrew final letters preceded by
> paddings / margins.
Not sure what you mean. To state the obvious, as opposed to Arabic where
the same Unicode character is used in any position in the word, and the
desired form is chosen by the renderer automatically, in Hebrew different
Unicode characters are used for the final and non-final forms (for those
few characters that have final forms).