Between 1902 and 1920, apart from the Austro-Hungarian Empire this banknote (AUSTRIA P-8) was in circulation in various European countries (Czechoslovakia, Hungary, Romania & Yugoslavia). In most cases out of Austria, it was overprinted (Czechoslovakia, Hungary & Yugoslavia), while in others an adhesive stamp had been put on its obverse (Yugoslavia - Croatia) or it was just hand-stamped (Romania). There are also mentioned cases that the adhesive stamp was forged, so the authorities had to cancel it using a hand “cancellation” stamp. I recently got a lot and among them there's one that bears an unreadable stamp, which doesn't match with the above info a got from my catalogue. So I would appreciate if any member of the community could help me understand this interesting field.
Possibly something as simple as a teller stamp? Most of the validation stamps like mine below for the re-issued Czech note are relatively tidy looking...
I would have to ask what the other stamps look like and if there similar If they are then probably just a variation of the same thing, do you have Another for comparison?