The travelling community has used symbols and signs as markers for centuries, to tell their fellow travellers following points of interest about a certain house, the area, etc.A rag tied to a tree, a twig bent a certain way for instance, can tell following families which way to go. Mostly, these are harmless, though can cause puzzlement; my grandmother couldn't understand why a steady stream of tramps, en route from Billesdon Union to Leicester, called at the house. The explanation was that she could not turn a beggar away without giving him bread and cheese. A more savvy neighbour pointed out the sign scratched on the gatepost which had signalled to his fellows that this was a 'good house'!
It's important to note the above, but not all these signs are innocent. Police in Lincolnshire recently issued diagrams of travellers signs which marked those properties which were ripe for crime, or even those were not worth thieving from. It's worth checking the boundaries of your property for any odd marks or broken twigs which could tell you what thieves think of you, your house, and what they might be planning.
Below are the symbols you should look out for. If you find one it would be wise to tell the police - and check your security.
From top to bottom they stand for:
'Nervous and Afraid'
'Not Worth Stealing'
'Too Risky '
'Already Been Burgled'
'Vulnerable Female Easily Conned'