Suppliers
Who stocks you — the starting point for purchase orders.
Needs Stock
A supplier is whoever stocks you. Setting them up does two things: keeps the contact where it's needed, and lets you build purchase orders in their name.
Adding a supplier
Select New supplier and enter a name, a contact person, an email and a phone.
The name is the one you use — "Sol Wholesale", not the legal entity on the receipt, unless they're the same.
Linking items
Items are assigned to a supplier from the item, not from here: open the item in Stock, select Edit, and pick its supplier.
The supplier's page shows every item you buy from them. That's the list you want in front of you when you call.
Deleting
Delete removes the supplier. Items that had them assigned are left without one; nothing else is erased.