dog tag

noun

1. a small disk or strip attached to a dog’s harness or collar stating owner, home, etc.
2. identification tag.
3. Informal.
   1. any tag for a suitcase, camera, or other personal possession with the owner’s name or address.
   2. a tag or card with a person’s name or affiliation, worn at conventions, large meetings, etc.

noun

1. US slang a military personal-identification disc