Hello,
TetraPak proposed a DQ rule for the tunisian fiscal number. The tunisian colleagues have approved the format as followed:
The Tunisian Matricule Fiscal combines several components and may be 7 to 20 characters in length. Leading zeroes should be added to the beginning of numbers that are less than 7 characters. The standard presentation is NNNNNNNX/X/X/NNN.
Sources:
https://taxid.pro/docs/countries/tunisia
https://profiscal.blogspot.com/2011/01/plusieurs-personnes-se-confondent-dans.html