A black banner reading "IS" appears to have been hung in the London borough of Hackney, in what was initially thought to be a marketing fail from the local council.
A picture of the banner, hanging from a lamppost and marked with "IS" in white letters, is being shared on Facebook.
It was originally posted by Alan Wolfson, who claims to have seen the banner in Morning Lane in Hackney.
The flag is apparently one in a series intended to create the sentence 'HACKNEY IS FASHION'.
But there was "no sign" of the other banners in the set except for the single "solitary" IS flag outside a Tesco, Wolfson said.
He wrote: "Hackney are draping banners around claiming it IS THE FASHION HUB. There’s no sign of the sequence of that sentence other than a solitary black flag with IS on it. Well done."
One commenter remarked "Great PR", while another simply said "facepalm".
Another posted: "You couldn't make it up, could you?"
But a spokesman for Hackney Council told the Metro that it has not put up the banner, though he confirmed seeing it in the street.
Instead, the flag is reported to be promoting a shopping centre.