All the responses so far are seem really helpful but also quite specific. It might also be useful to understand the problem space at a higher level. We also see

All the responses so far are seem really helpful but also quite specific. It might also be useful to understand the problem space at a higher level. We also see this in good database design. Which says that every record should always have a unique id that is not related to any of the other data. This allows you to freely change things like product descriptions, short name, SKU, price, weight, etc. Because you know that no matter what else changes, you have a unique ID to refer back to, that will get you to that product. Since a unique ID is often a random looking string, there is nothing stopping you from also having a human friendly lookup code for a product. For example, unique id is 186746, but the lookup code is BRWNCOUCH37. If the couch doesn't change color, the lookup code stays good. But if it does, you can change even the lookup code. Because the product unique id remains 186746. So unique IDs are useful in many places other than just error codes. Hope that helps.