1950 1st airmail / PO's, rates & routes: 31-7-1951 'official mail' government stationary surface mailed cover from department of collections & property tax HAIFA to USA, franked 30pr at the SU-2 period rate using 30pr single (Ba33) tied by single strike of Haifa head post office postmark, with Israeli "official mail" cachet on front - scarce as overseas mail; slit open at top. Official mail was free for regular inland service, until February 1951 and then again from June 1952; in any case the overseas mail rate had to be paid, so the cover was likely pre-marked official mail stationary.