John Cowan wrote:
> Marco Cimarosti scripsit:
> > In addition to the standard marks, religious text often use
> > "filling" marks (generally shaped like little "v"'s) to
> > fill up all the blank space where additional marks could
> > conceivably be placed, in order to avoid any possible
> > alteration of the text.
> Is this encoded in Unicode?

I don't think.

> If not, does it need to be?

No, IMHO that has to be regarded as text decoration, pretty like the fairies
in this "S":

It does actually also have that utilitarian function of avoiding
modification of the text, but that's also true of, e.g., the diagonal line
often seen on Western digit zero, or the crossbar seen on digit seven:
elements which are seen as glyph elements in Unicode, and certainly not
encoded as separate diacritic characters.

Moreover, the presence, number and position of these marks depends strictly
on the graphic appearance of the Arabic letters in that word and in that
calligraphic style. Any blank area big enough to host a diacritic mark is
sort-of barred out with that sign. But, in Unicode context, whether or not a
certain letter leaves a blank area big enough depends on the design of the
font, hence it doesn't belong to the encoding.

Perhaps, automatically adding such signs could be a feature of a
"science-fiction-level" OpenType font.

_ Marco