Go to Setup > Yes/No Options > Confirmation Tab.
Programmable Bar Codes for Stock Purchases can be configured by going to Setup > Global Options > Purchases > Programmable Barcodes.
Prefix – All barcodes starting with this prefix will be considered as a programmable barcode.
Field 1 – Choose either Stock Code or Department Code.
Field 2 – Choose either Price or Qty.
Position Fields – Enter the starting position for Field 1 & 2.
Length Fields – Enter the length of the fields for Field 1 & 2.
Decimal Point – Enter the decimal point position when using Price for Field 2.
Various permissions can be configured for User accounts to control what they can and can't access.
Go to Setup > Users > Modify a User other than Admin > Transactions > Stock Control.
The File > Stock Control > Stock Items > Supplier Codes User Permission is applied to Stock Purchases - when you browse Supplier Stock Codes it hides the "New" button.