Period of detention set off against imprisonment, reducing custodial term to the remaining period; special cap rule applies. An accused's period of detention during investigation, inquiry or trial before conviction shall be set off against any sentence of imprisonment imposed on conviction (excluding imprisonment in default of payment of fine), and the person's liability to undergo imprisonment is limited to the remainder of the imposed term; where a specific fourteen year cap provision applies, such detention is to be set off against that fourteen year period.