ORS § 90.148
The surrender of a dwelling unit may be implied from the landlord's acceptance of a tenant's abandonment or relinquishment of the right to occupy. The landlord's acceptance may be demonstrated by acts of the landlord that are inconsistent with the existence of the tenancy. A landlord's receipt of the keys to the dwelling unit or a landlord's reasonable efforts to mitigate the landlord's damages by attempting to rent the dwelling unit to a new tenant shall not constitute acts inconsistent with the existence of the tenancy. Reasonable efforts to mitigate damages include preparing the unit for rental.
ORS 90.148
90.148 was added to and made a part of ORS chapter 90 by legislative action but was not added to any smaller series therein. See Preface to Oregon Revised Statutes for further explanation.