The section could have been summarized in the sidenote as 'arrest for non-arrestable offences', but the draftsman did not dare to risk such Kafkaesque accuracy.

Section 24 was supplemented by a section 25 which created new powers (for constables only) to arrest those suspected of "non-arrestable offences" in certain circumstances.

In addition to being able to arrest for an arrestable offence as defined above, section 25 provided further powers of arrest for "non-arrestable offences" in certain circumstances.

Under section 25 the police have a power of summary arrest in the case of non-arrestable offences, but only where service of a summons appears to the officer to be impracticable or inappropriate because any of the general arrest conditions noted below apply.

Sections 24 and 25 were controversially amended by the Serious Organised Crime and Police Act 2005, which abolished the difference between arrestable and non-arrestable offences and substituted one set of police arrest powers for all offences, irrespective of the maximum sentence.