Collectors who do not read Khmer would conclude that this mail was sent at the Sihanoukville post office, since they can only recognize the geographic name "Sihanoukville" on the two different postmarks.
The city of Sihanoukville has two post offices. The large postmark belongs to the branch office in Phsar Loeu (New Market), it is located in down town area. The geographic name "Phsar Loeu" is inscribed in Khmer within the upper rim of the postmark.
The small postmark belongs to the main office. The main office is near the City Hall which is in Weather Station Hill area near the Victory Beach.
This mail was sent at Phsar Loeu office, then taken to the main office and so received the main office arrival postmark, and then delivered to Phnom Penh to fly to Germany.
Postcode for the main office is 18000. Phsar Loeu postmark used to show 18200, now it becomes 18000 (see the large postmark).
Sihanoukville is a coastal city founded in 1960 to be the first deep water port of the country. Suffered from 30 years of war, picturesque Sihanoukville attained peace and stability only a decade back, she is now quickly picking up as the hottest holiday town and trade port of Cambodia again.