Is it a password, is it a joke or could it even be Russian code?
Donald Trump's cryptic middle-of-the-night Twitter sign off has sparked all of the above suggestions as the phrase "covfefe" went viral on social media.
The US president's unexplained word, which at first glance appears a typo, has inspired a fantasy Twitter spat, countless gags and - before you even look to cash in - been bought out as a website and sold as a t-shirt.
Here's the best selection of the reaction to his 5am tweet:
- Could covfefe be an acronym?
- Will he wake up and realise he misspelled coffee?
- Is Trump speaking a different language?
- Is it a (dangerous) code?
- Covfefe inspires a host of memes and videos
- It sparked warring wizards and vikings
- Some enterprising folk looked to profit from the craze
- Others found a new covfefe twist on old phrases
- Finally, the most plausible: he misspelled coverage, didn't he?