  Diacritical marks play a crucial role in meeting the criteria of usability of
typographic text, such as: homogeneity, clarity and legibility. To change the
diacritic of a letter in a word could completely change its semantic. The
situation is very complicated with multilingual text. Indeed, the problem of
design becomes more difficult by the presence of diacritics that come from
various scripts; they are used for different purposes, and are controlled by
various typographic rules. It is quite challenging to adapt rules from one
script to another. This paper aims to study the placement and sizing of
diacritical marks in Arabic script, with a comparison with the Latin's case.
The Arabic script is cursive and runs from right-to-left; its criteria and
rules are quite distinct from those of the Latin script. In the beginning, we
compare the difficulty of processing diacritics in both scripts. After, we will
study the limits of Latin resolution strategies when applied to Arabic. At the
end, we propose an approach to resolve the problem for positioning and resizing
diacritics. This strategy includes creating an Arabic font, designed in
OpenType format, along with suitable justification in TEX.
