Apple is due to show off some of its new products for 2018 later on today, but somebody at the company has dropped a bit of a clanger by revealing the names for its three new iPhones on its official website – as well as loads of other data which, we're assuming, Tim Cook wanted to share himself.

The info was spotted by All Things How in a product sitemap XML file hosted on Apple.com before it was quickly pulled. The file not only details the names of the three shiny new iPhones – iPhone XS, XS Max, and XR – but also mentions the Apple Watch Series 4 as well as new watch band sizes. Oops!

Keeping on the topic of the Apple Watch for a second, the file teases that new watch bands will come in wider 40mm and 44mm sizes – existing bands are either 38mm or 42mm. A wide range of colours will also be available.

The iPhone XS would appear to be an update of last year's groundbreaking iPhone X, while the iPhone XS Max will be the larger-screen variant. We previously reported that Apple may be using the 'Plus' name for its large-format phone, but this leak would appear to confirm that the naming convention is finally being put to bed. The iPhone XR – which many assumed would be called iPhone XC in reference to the mid-range iPhone 5C from a few years back – is presumably the all-plastic, low-cost iPhone that has been rumoured for months.

That's not all; the file also reveals that Apple is planning a series of new cases for the iPhone XS and iPhone XS Max. The silicone examples will come in midnight blue, white, black, stone, and Product RED, while the leather cases – a firm favourite with previous Apple phones – will be available in saddle brown, taupe, black, and Product RED. We're also getting leather folio cases in black, Product RED, green, Cape Cod blue, and peony pink. Interestingly, no official Apple cases are listed for the iPhone XR.

This isn't the first time that Apple has ruined its own big surprise; back in 2017, its Twitter account announced the iPhone 7 before it was officially unveiled. We imagine the person responsible for that tweet – and perhaps even this latest leak – may be looking for employment elsewhere.

Apple is due to show off its new products today at 10AM PDT / 6PM UK time.