Officer in charge of a police station [SHO]

2(o) “officer in charge of a police station” includes, when the officer in charge of the police station is absent from the station-house or unable from illness or other cause to perform his duties, the police officer present at the station-house who is next in rank to such officer and is above the rank of constable or, when, the State Government so directs, any other police officer so present;

The Code of Criminal Procedure 1973