Swedish Narvik Volunteer´s Dog Tag

I was recently presented with a very special dog tag that I will shortly pass on to the Defence Museum in Boden/Abisko. I have never seen one of these before, and would appreciate some more info about them.

Here it is, the dog tag worn by Swedish volunteer Jan Danielsen at Narvik:


The front, which only states NORSK, meaning Norwegian, and then has the etched rank FENRIK meaning 2nd lieutenant + DANIELSEN.


The back, which states I/IR 16 meaning I battalion of the 16th Infantry Regiment.

Jan Danielsen, with whom I recently attended the 70th anniversary ceremonies in Narvik, has kept it all these years, forgotten about it and then recently found it.

I would really like to know if this was standard operating procedure, i.e. that everyone etched their own rank, name and unit? Also, were they most usually worn by means of a piece of string or a chain? Please do reply by means of the commenting function of this blog.

Considering that there were only a dozen Swedish volunteers at Narvik this tag must be rather unique.