An online shopper was given one of the weirdest substitutes ever by Asda recently: a bottle of whisky in place of baby wipes.
Freelance copywriter Art A has tweeted a photo of an Asda receipt - which he said wasn't his - captioned 'Greatest. Substitute. Ever'.
It shows that, because the customer's £6.64 packet of baby wipes wasn't available, staff at the Plymouth branch of the store replaced with a £18.50 litre bottle of Bell's Whisky instead.
The photo's now been shared more than a thousand times on Twitter, with several people suggesting that perhaps the whisky was designed to help the stressed parent cope.
Asda has since spoken to ITV West Country, saying it has spoken to the customer and arranged for the wipes to be delivered.
"The customer was happy with this and even happier to keep the whisky," a spokesperson said, adding that staff in the local branch would be given further training on substituted items.
Supermarket substitutions are sometimes extraordinary. Tesco, for example, once sent a whole octopus to a customer who'd simply wanted walnut bread.
Not to be outdone, when Asda didn't have any sugar-free sweets it sent five tins of pilchards instead. Sainsbury's, meanwhile, chose to substitute blackberries for potatoes for one shopper, and lemon-scented Flash for fresh lemons for another.
On Twitter, customers complain of having been sent cress instead of garlic, a cheese tart for deodorant and a Brillo pad for turkey mince. One asked for organic houmous and got plaice fillets instead.
Most supermarkets allow shoppers to opt in or out of being given substitute products - but the extent to which they do substitute varies. In a Which? survey, Asda was rated worst for substitutions, with 51% of customers complaining that they got one.
Tesco and Waitrose were the next-worst offenders, with substitutions in 39% of orders. Iceland orders were the least likely to contain substitutions, says Which?, while Waitrose customers were the most satisfied with the substitute items they were given.
And for many customers, it matters. Vegetarians won't be happy to get meat instead of veg, for example. More importantly, people with diabetes or food intolerances can often be sent products they can't eat.
Some supermarkets allow customers to choose which products may be substituted, or specify, for example, vegetarian-only; so it's worth shopping around.