On 9th July 2009 I wrote about a 1979 diplomatic mail from the Kampuchean embassy in Beijing of China (click here to read).
Here is a 1976 cover from the embassy for comparison:
Back of cover:
Postmarked 30th April 1976 in Beijing, this cover was sent to the East German embassy. It is the ink stamp on the back which catches my attention. The black ink Chinese stamp says "Telecommunication Receive & Dispatch Seal of Embassy of [spacing] Cambodia in China". Right after the three characters for the word "Cambodia", there leaves spacing of two Chinese characters.
The Chinese equivalent of the word "democratic" in "Democratic Kampuchea" takes up two characters, but they are put before "Cambodia", not after. A reasonable guess is that the two missing characters are "Wang Guo", which literally means kingdom; in Chinese grammar the word "kingdom" is put after the country name. And so the embassy used the old ink stamp of Sihanouk era but scraped off the characters for "kingdom".
The Khmer Rouge took power in April 1975 yet after a whole year its embassy in the capital of the Maoist group's best ally was still using a Sihanouk era old ink stamp.
Cambodia changed her name from "Kingdom of Cambodia" to "Khmer Republic" in 1970, and from 1975 to 1979 Cambodia was formally known as "Democratic Kampuchea".