Police are warning people about carrying small items that could be seen as a dangerous weapon.
It comes after a 21-year-old man was given a fine of £175 after police found he was carrying a small knife on a keyring.
The knife was under 3 inches long but it was said to be dangerous enough that the male was charged with possessing a knife blade or sharp pointed article in a public place.
PC George Rabczak at Wiltshire Police said, "The male argued that the knife was under three inches and could not do any damage.
"This is clearly not the case as the sharp-pointed tip and jagged edge could cause serious injuries if used in a violent manner.
"I would urge anyone to think carefully about what they carry in public as anything which could be used to cause harm could result in you getting arrested and charged."