Unique "Prefix" and "Suffix" at the store level

Lets say I have 6 websites stores (A-F)

A = Main site
B = Company A store
C = Company B Sore
D = School Fundraiser
E = Contractor site
F = Pre decorated site

I'm looking for a way for invoicing to start with a letter in each of the site that corresponded to a predetermined prefix for easy ID when order come into the hub.

For my example I would have 6 different prefixes, one for each website store, as to identify an order.

Having DN to assign prefix at each store level makes sense in using prefixes and suffix. 

What's the point of having prefixs and sufixx then if all the invoices will have the same prefix and suffix

Currently prefix and suffix are a global setting, all invoices have same prefix and suffix.