Allowed number of digits for credit / debit cards

In Chapter 2.5 of the 28th August draft (3rd bullet point) it is stated that 
credit cards may have only 14, 15 or 16 digits.

Strictly speaking that may be true (as far as credit cards go) but many 
online sellers who accept credit cards also accept debit cards. One of the 
debit cards I have has 18 digits.

A small point I know but most businesses won't want to turn away business 
because of an appropriate restriction on the number of digits relating to the 
method of payment.

Andrew Watt