"Di" stands for "diacritics" – the font features multiple versions of them based on historical forms. "Grotesk" refers to the early 19th-century sans-serif fonts the typeface draws upon. The height in the upper case letters is smaller than in the minuscules with ascenders, which provides additional room for diacritics. The diacritics signs, in turn, have variants derived from various typographic traditions - from incunabula to the substitute solutions of the shortage economy of People’s Republic of Poland.
XVII century early diacritics marks applied by Polish printers.
This is an old XVII century way of dealing with Polish “Ą”. Why not to use this kind of treatment today?
You have three extra stylistic sets with special design of “Di”-acritics. All based on historical forms.
Additional stylistic sets.
Non dogmatic construction of “Ą”.