Documents and miscellany can offer a wealth of information for researchers, historians and even artists. But what happens if the item in question is fake? How do you know? It takes a learned eye.

The image above was taken from the website of The Society of Indo-China Philatelists (um, that means, stamp collectors). According to their site, the above item was indentified as fake because the:

1. Cover known to have been made in 1975, shipped overseas

2. Overprint is fantasy (a few trials exist, never used). Nge Khe used French Indo-china stamps after liberation. This P.O. is a branch located on a French plantation with two postal workers to service the workers of the plantation. There was no need for all of the so-called stamps, and no ability to print overprints.

3. The cachet is taken from a 1950s piece of paper money.

4. The slogan is from a Dec 19, 1946 event

5. Cancel states Interzone 2 (Lien Khu II). Nge Khe was in Interzone 3 (but not until 1946), never Interzone 2.

There are other address and province errors. 

The site offers a number of interesting images of both real and fake stamp and cancels from the French colonial period to the current Republic of Vietnam. Go to the site to find out why this one is a fake. Each one is stamp-sized detective story. 

Source
Website. The Society of Indo-China Philatelists