^ dog tags = the [unofficial?] term used by soldiers when referring to the small metal ID plates they wear, usually around their necks on a chain.
These things contain basic stuff like name, rank, unit, ID# and possibly blood type I believe. I think the name came from the resemblance of these small plates to actual ID plates that are used on dog/animal collars to identify them.
<apologies for long winded explanation if you knew the above, but I see you are from Oslo so perhaps are unaware of this...>