A self-declared "grammar vigilante" is spending his nights prowling the streets of Bristol and correcting the punctuation on business signs.
Among the mystery man's targets have been signs reading "Vicenzo and Son Gentlemens Hairstylists", "Herberts the Bakery" and a greengrocer display advertising "potato's".
The vigilante, who goes out late at night wearing a black coat and hat, has been correcting the city's bad punctuation for more than ten years.
"The first one I did was way back in 2003", he told a reporter. "There was a council sign that said 'Open Monday's to Friday's' and it had these ridiculous apostrophes. I was able to scratch them off.
The man said he had made an eight-foot-long tool he calls an "apostrophiser". This allows him to stick punctuation marks on to high-up displays. He also uses a specially-made stepladder that enables him to work without leaning against shop windows.
The grammar vigilante, who uses stickers rather than paint to make his changes, says his "heart is pounding" during his work but denied his alterations amounted to criminal damage.
"I don't think it's damage", he said. "What i'm doing is sticking on a bit of stick-back plastic. It's a worse crime to have all these errant apostrophes on shops and garages. I just think it's going to teach the youth of today the wrong grammar."
All this just goes to show that you should always use a reputable sign company when displaying your brand image to the public.