The most exciting unlisted stamps of Cambodia are the surcharges. Since they were locally handstamped for postal use with no philatelic sales, overseas collectors have had a hard time identifying and collecting them.
After a long time of putting together bits and pieces of information, 19 surcharges have been recorded:

To spice it up, the original 1988 folk dance set has two stamps with a variety of inscription errors, they were surcharged alongside with the regular stamps.
Here is a genuine set of the folk dance surcharges with 1r variety.

More unlisted surcharges may exist, further research has to be done for a better picture.
Almost all 1990s surcharges have forgeries. Fellow collector Jean-Marie Florent of Belgium is kind enough to scan some for our reference, thank you Jean-Marie.












