Police are warning people in Caterham to be vigilant after two incidents where symbols were etched on pavements. Five circles can indicate to criminals it is a wealthy household.
Criminals have used symbols and markings to communicate with others for centuries. This sign means the house is fitted with a burglar alarm.
This symbol or something similar can indicate the home has already been burgled and is therefore not worth investigating further.
Inspector Elaine Burtenshaw from Surrey Police said various symbols mean various things. In this picture it shows the house is a "good target".
A drawing of two interlinking rectangular shapes can be used to show the occupants are nervous, possibly afraid and may be easily conned.
A number of homes in Surrey have been targeted in this way recently. The sign above is used to mean there is nothing worth stealing at the property.
Kerbs, low walls and pavements are the most likely places to be inscribed, as they are not immediately obvious. This symbol can mean there is a possible risk to the criminal at the property.
Surrey Police say that another known symbol is a drawing of an open book which is used to indicate a vulnerable female was inside a property.
Anyone who sees symbols chalked outside houses is urged to contact Surrey Police. Contact numbers are above or using the web link on this page.