The Pashto letters most tools miss
Pashto adds letters that aren't in Arabic or Persian — ټ، ډ، ړ، ښ، ږ، ځ، څ، ڼ, among others. Many fonts and PDF tools don't include them, so a filled form ends up with gaps or square boxes. RevivePDF embeds a font that covers the Pashto alphabet and lays the text out right-to-left.