Its hard to tell, are they European or Japanese?
Where did you find them?
You can put a small current throu them, and check the voltage between anode and cathode.
Try 0.1, 1 and 10 mA.
staigen well its just the diode and continiuity tester all in one and i think its the forward voltage but ill have to check the instructions again as for what nationality well it depends on if your refering to the maker of my digital meter or diode , as for diode well its to small for anything else to go on it