It can be used as a means to identify a person.
Again, consider the example of the medical test used to identify a disease.
The number is used to identify the computer to the local network.
His name has also been used to identify the post office between 1929 and 1967.
It is used to identify the potential impact of a project on the environment.
Your name and social security number are not used to identify the trust.
Different terms can be used to identify the same concept.
"Anything special about this you could use to identify it?"
So, it can also be used to identify the various elements present.
Oh, and I'll give you something to use to identify which patient each sample comes from.