 But the Nastaliq style in which Urdu is written uses more than three general forms for many letters, even in simple non-decorative documents.The Urdu script is an abjad script derived from the modern Persian script, which is itself a derivative of the Arabic script.As an abjad, the Urdu script only shows consonants and long vowels; short vowels can only be inferred by the consonants' relation to each other.