"identifier" - key terms from Wikipedia

bank identifier	code
country identifier
digital object identifier
field identifier
fragment identifier
globally unique identifier
group identifier
host identifier
identifier
identifier	defined
identifier	scheme
name identifier
network identifier
object identifier
openid identifier
public identifier
resource identifier
security identifier
serial item and contribution identifier
uniform resource identifier
unique court identifier	code
unique identifier
unique integer identifier
unique session identifier
universally unique identifier
virtual channel identifier