Aus and NZ have now been included in the Mystery Code promo. So that means the codes are good for use in UK CA US AU and NZ.
Some may be particularly impressed with NZ's inclusion.
There's now NO disconnect between what the promo info says:
Get from
10%-90% OFF select eBooks
and the Fine Print:
Spoiler:
Discount code is valid on select eBook purchases from this page. Discount will be confirmed at checkout. Offer valid from June 19, 2015 at 12:00 AM EST through June 23, 2015 at 11:59 PM EST. This offer is not valid in conjunction with any other offer or promotion and cannot be used to adjust amount paid on previous purchases. Discount code must be entered at time of purchase to qualify for this discount. Discounts cannot be applied nor the discount value refunded once a purchase is complete. Rakuten Kobo Inc. reserves the right to change or cancel this offer at any time without notice. Coupon value distribution coupon value 10% distribution 15%, coupon value 20% distribution 15%, coupon value 25% distribution 30%, coupon value 30% distribution 25%, coupon value 35% distribution 13.5%, coupon value 45% distribution 1%, coupon value 50% distribution 0.5%, coupon value 75% distribution 0.2%, coupon value 90% distribution 0.15%.
Edit
And my first code is 10%. So hmmmm, not much point, eh!