it's possible to fix our heuristics but it's likely to regress some other site somewhere. Could Mr Frank be persuaded to add this to his <input>: autocomplete="purchase-quantity"

Hello, Steven reporting in.  :)

For now I'm using autocomplete="off" on that field which has remedied the immediate problem, and is a workaround I'm satisfied with.  I'm curious what the motivation is for autocomplete="purchase-quantity" as it's hard to imagine a situation in which I would want a purchase quantity autofilled?

I agree that it would be tricky for you to address this without affecting someone else down the road.  Our situation is probably unique, it just happened to be the perfect storm for us -- we had two customers in the span of a month who accidentally charged approximately $20,000 to their credit cards instead of the $99 they were expecting, because the purchase quantity field got populated with their three-digit area code when they autofilled their address.  After the second incident, I was finally able to track this down as the root cause.

> it's hard to imagine a situation in which I would want a purchase quantity autofilled?

This would be useful for a customer that always charges the same amount.

Thanks Steven, 

autocomplete="purchase-quantity" is a sure way of making sure Chrome will not autofill, because Chrome doesn't fill fields that have unrecognized autocomplete attributes.

I'm going to mark this as WontFix for the reason estade@ mentioned above. 

Thanks for the feedback

right, autocomplete="purchase-quantity" wouldn't be autofilled at all by any sane browser. It just tells us what the field is so we don't confuse it for an area code.