Public IDs

Public IDs are stable, globally unique, non-recycled strings. Prefixes help detect type mistakes; they do not grant authority or encode business meaning.

Prefix	Resource
mer_, loc_	Merchant, location
prod_, cat_, mod_, disc_	Product, category, modifier, discount
imv_	Inventory movement
cus_, ord_, pay_	Customer, order, payment
sup_, po_, fisc_	Supplier, purchase order, fiscal document
evt_, whd_, op_	Event, webhook delivery, operation receipt

Do not infer database UUIDs, parse suffixes, or construct an ID. Inventory levels intentionally have no ID; their logical identity is (product_id, location_id).