In both the original Codex icon set and the T399175: [EPIC] Refine Codex icon library redesign, the Arabic version of the bold icon, using the character ayn (ع), has a more calligraphic-like font with variable line weight. Meanwhile, other Arabic script icons in the set (Persian and Urdu bold, and Arabic, Persian and Urdu italic), all use characters with constant line weight. In fact, the Arabic italic symbol appears thicker than the bold symbol at first glance!
Having a common font would help with the consistency of the design language. This was touched on in T427868: Icon refinement follow ups, with the recommendation being to create a new task specifically for that matter.
Additionally, the italic characters don't seem to be visibly slanted, making it hard to parse whether the text will display as regular right-slanted italics or left-slanted "iranics", both of which are used in Arabic scripts.
| Language | Bold | Italic |
| Arabic (ar) |  |  |
| Persian (fa) |  |  |
| Urdu (ur) |  |  |