I call this knot the carrick bend loop. The lower knot is a lanyard/diamond knot for size comparison. carrick bend loop tutorial
I'm sure it could. I'd tie a short length for the tag base, then attach a metal 'dog tag' with personal info to that with smaller diameter cord. I'd think there would be other ways to do it as well, so that's just one option...
first of 3 luggage tags. Just something unique to help ID luggage other than reading the name tag on them now to make 2 more for the friend that asked for them. And I will probably make some similar ( different colors ) for myself