informed consent identification code #2

We have a class "informed consent identification code" that is a data item. There is no annotation on this code to indicate what it represents. Candidates for the annotation would logically include:

1. the IRB number associated with the approval of the informed consent instrument
2. a unique (system generated?) code or sequence number associated with the process of successfully executing a legally valid informed consent

I suspect the intent is (2), but this needs an authoritative definition from an accepted definitional source.