我只看的notes,明确写的是:
Past (prior) service costs are retroactive benefits awarded to employees when a plan is
initiated or amended. Under IFRS, past service costs are expensed immedi ately. Under
U.S. GAAP, past service costs are amortized over the average service life of employees.
Actuarial gains and losses are recognized in other comprehensive income (OCI). Under
IFRS, actuarial gains and losses are not amortized. Under U.S. GAAP, actuarial gains
and losses are amortized using the corridor approach.