Missing Perforation: postage stamp with not executed perfor-ation caused by error (imperfor-ated) |
Partly Missing Perforation: postage stamp with partly not executed perforation caused by error |
Perforation Number Error: philatelic term for a deviation from the intended perforation number caused by error |
Partly Perforation Number Error: philatelic term for a partly deviation from the intended per-foration number caused by error |
Inverted Perforation: postage stamp with 180 degrees rotated perforation caused by error |
Double Perforation: postage stamp with twice instead once perforation caused by error |
Partly Double Perforation: postage stamp with partly twice instead once perforation caused by error |