useful link www.ico.gov.uk

Signs should be placed so that the public are aware that they are entering a zone which is covered by surveillance equipment (First Data Protection Principle).
The signs should be clearly visible and legible to members of the public (First Data Protection Principle) The size of signs will vary according to circumstances:
For example - sign on the entrance door to a building society office may only need to be A4 size because it is at eye level of those entering the premises.
For example - signs at the entrances of car parks alerting drivers to the fact that the car park is covered by such equipment will usually need to be large, for example, probably A3 size as they are likely to be viewed from further away, for example by a driver sitting in a car.

The signs should contain the following information:
a) Identity of the person or organisation responsible for the scheme.
b) The purposes of the scheme.
c) Details of whom to contact regarding the scheme.
(First Data Protection Principle)

For example - Where an image of a camera is not used on a sign - the following wording is recommended:
" Images are being monitored for the purposes of crime prevention and
public safety. This scheme is controlled by the Greentown Safety Partnership.
For further information contact 01234-567-890"
For example - Where an image of a camera is used on a sign - the following wording is recommended:
" This scheme is controlled by the Greentown Safety Partnership.
For further information contact 01234-567-890”
(text in red indicates good practice)