Residency in Malta for non-rich, non-EU, non-UK citizens.

Hi,
I have recently received an e residence card for one year as a self sufficient retiree non EU citizen, Form K.  All requirements for Form K are listed on the government site.  In spite of having been many times discouraged from bothering to try, I submitted all required documentation and, after 3 months, finally received e residence card.  Renewable possibility but no guarantees.  I was initially told self sufficiency for non Eu people was no longer available.  May depend on which country you come from.  Managed initially to wheedle my way in to see someone higher up which may have helped.    Ozchook

on the "Global" checklist given us at the Citizenship and Expat office, there is a requirement for a "letter from income tax unit at Mriehel".  Does anyone have any idea what this is and how to obtain it?