Barcodes can today only be inserted without spaces (including trailing or leading (BB-495)) and not in the more common format of "9 788205 174238"
Additionally when doing so they will be auto-corrected to ISBN-13 (BB-508)

as ISBN usually come in the format of ##########, ############-# or ### # ## ###### # and pasted barcode will come usually in the format of # ###### ###### the selector should be able to be clever and figure out if it's ISBN-10, ISBN-13 or BARCODE/EAN/UPC

if it cannot figure it out, then it should just remain unselected until input by user.
additionally instead of not being able to add an unusual barcode/isbn there should be a ticketbox with "this does look like a valid $selected-type, are you sure this is correct" to permit rare situations - this will mirror MB's such for barcodes

When storing the Barcode (and ISBN) it should be stored as a x-digit string in the database, but displayed as pasted. For search all spaces and hyphens should be ignored.