https://wiki.openstreetmap.org/wiki/Key:ref:
int_ref=*– international reference numbers or codes
loc_ref=*– local reference numbers or codes
nat_ref=*– national reference numbers or codes
https://wiki.openstreetmap.org/wiki/Key:int_ref:
“int_ref” stands for “international reference” and is used for international reference numbers or codes.
https://wiki.openstreetmap.org/wiki/Key:nat_ref:
National reference (“Nationally referenced as…”).
I see the most concrete concepts possible. Nothing at all points to vagueness. What did you see there that was vague?