The station clerk’s duties necessitate his continuous presence at the police station; accordingly he shall not be employed on investigation work or any other duty involving his absence from the police station for any long period. If he leaves the station house for any purpose which is likely to prevent his return within a few minutes on an urgent summons, or under the provisions of rule 22.42, he shall formally make over charge to the assistant clerk and shall make an entry in the daily diary. Similarly, on return to duty, he shall again enter the fact in the daily diary and both entries shall be signed by the assistant clerk as evidence of his responsibility during the absence of the station clerk. Under no circumstances shall the station clerk and the assistant clerk be both absent from the police station at the same time.