Finding pins for relay
If you have 50 of them, one easy way to figure the pins out would be to crack one open and have a look inside. The coil and connections should be clearly visible. 

Another way is to use some Google-Fu and try the code or parts of it (you can add "relay" or "datasheet" to help narrow things down) and you may come up with something. I just had a go and I think this looks like your part's datasheet.



It should look something like the above if it is the right datasheet.
If you look closely you can see a similar format for rest of your code on the package example (the ARK-110 612 25W bit) 

Since yours appears to the "single side stable version", this should be the pinout for it: