LONDON (AP) — It's an urban myth come true — the presence of a man dedicated to ridding the English city of Bristol of grammatical errors in its shop signs.

He goes out at night with a self-styled device used to cover up misplaced apostrophes from street signs in the city 120 miles (195 kilometers) west of London. He uses stickers, not paint.

The man has not been identified but he told BBC in a report broadcast Monday that he doesn't consider his alterations of the signs and store fronts to be a crime. He says the real crime is putting apostrophes in the wrong places to begin with.

It's not a new obsession — he's been at it for 13 years.