How are lease incentives handled before applying ASC 842 and IFRS 16 Accounting

There is no Lease Incentive option on the financial terms page until ASC 842 and IFRS 16 Accounting is applied. How was lease incentives handled in the lease module before applying ASC 842 and IFRS 16 Accounting? I know the feature is not available until 842 is turned on but there should be a way to address lease incentives in 840. Reason being that we will be turn on the lease module 1/1/19 in the old standard (840). We will turn on the new standard (842) 1/1/20. We need to account for lease incentive (for straight line accounting) in the old standard for year 2019.