Need help understanding "customer_pos_id" field

When I set up an import of customer data to ERPNext, I noticed the field “customer_pos_id”

I am looking for some answers about this field:

1.) How is it used in the system now?

2.) Where can I access it in the user interface?

3.) Can I safely make use of this field for my own purposes in the POS module and feel sure that it will not be removed from the system in some later version?

Thank you in advance for any help you can provide that gets me closer to understanding how this field works.

NOTE: If I find it is not used much, then I will use it as a customer id field for POS and it will simplify my customer look-up later in the POS module.

BKM

Is this field actually used anywhere right now?

BKM