The ICO has published detailed guidance on criminal offence data aimed at data protection officers or those in larger organisations with specific data protection responsibilities. The guidance includes information on what criminal offence data is, what the rules on criminal offence data are and what the conditions for processing are. 

Under the GDPR, "personal data relating to criminal convictions and offences or related security measures" is given extra protection. The ICO refers to this as "criminal offence data", which covers wide range of information such as criminal activity, allegations, investigations and proceedings.