Regina 80 marked chain?
 

I just replaced the chain on my bike this afternoon, as it was starting to reach the end of its useful life. Didn't realize until after I got it off and cleaned it up a bit (planning to make a bracelet out of a bit of it), that it's a Regina brand chain. It's marked REGINA 80. Out of curiosity, is that a date stamp (i.e. 1980), or the model of the chain?