. this reserve is calcu- lated using an estimated obsolescence percentage applied to the inventory based on age , historical trends and requirements to support forecasted sales . in addition , and as necessary , we may establish specifi c reserves for future known or anticipated events . pension and other post-retirement benefit costs we offer the following benefi ts to some or all of our employees : a domestic trust-based noncontributory qual- ifi ed defi ned benefi t pension plan ( 201cu.s