Why it matters
Separating a lookup key from working data can limit routine exposure. That separation only helps if access to the key, the coded records, and any other identifying information is deliberately controlled.
A practical example
A hypothetical biobank labels a sample with a study code. A separate record links that code to the participant so authorized staff can handle withdrawal or return a result when appropriate.
An important distinction
Coded data is not necessarily anonymous. The lookup table is one path back to identity, but genomic matches or distinctive metadata may provide others. Protecting the key and assessing the coded dataset are related but separate tasks.
Sources and further reading
- PRIMARY SOURCE NIST SP 800-188: De-identification
The example above is hypothetical. Related cases provide context; they do not imply that every case involved this mechanism.