A quick definition of et sic de anno in annum quamdiu ambobus partibus placuerit:

Term: ET SIC DE ANNO IN ANNUM QUAMDIU AMBOBUS PARTIBUS PLACUERIT

Definition: This phrase means that something will continue from year to year as long as both parties agree to it. It is often used in reference to a lease, where the landlord and tenant have not indicated whether they want to renew the lease or end it. If they do not say anything, the lease will automatically renew for another year.