Referencing non-DOI PIDs

If you were to use PIDs to provide specific granularity/subsetting/aggregation how should these be referenced in a paper. Should this be in supplementary information?

We are planning on providing PIDs on our data at greater granularity to the DOI so to inform on the data used, so it might be beneficial to provide a list of PIDs and wondered if there is currently a recognised way to do this?

Thank you