One of the principles around which the Code is built is transparency, which includes a statement that 'Chief officers must ensure that, where appropriate, their force is transparent with the public about the nature and type of records and information they hold, and how and why their information is being processed'. In terms of accessibility the Code states 'Chief officers should ensure that systems are in place that make it easy to understand what information the force holds. The information should be stored in a way that ensures its efficient retrieval'. Certain police records are archived for their historical value and enduring public interest, for example those involved in major investigations such as a murder. Chief officers should ensure their force has systems and processes in place to identify records that meet the criteria for permanent preservation.