Bonds offered as a tranche class of some CMO's , based on a sinking-fund schedule. However, they differ from PAC bonds in that whereas a PAC's amortization is guaranteed as long as prepayments on the underlying mortgages do not exceed certain limits, a TAC's schedule will be met at only one prepayment rate.
TARGETED AMORTIZATION CLASS (TAC) BONDS
Meaning of TARGETED AMORTIZATION CLASS (TAC) BONDS in English
Campbell R. Harvey. Hypertextual finance English glossary. Английский словарь гипертекстовых финансов. 2012