The Pennsylvania Supreme Court in interpreting sections 5(1) and 5(3) of the Principal and Income Act of 1947 has held that mutual fund distributions designated as realized capital gains are allocable to principal.
In Re Estate of Brock, 420 Pa. 454, 218 A.2d 281 (1966).
Richard E. Myers,
Trusts - Principal and Income Act - Mutual Funds,
Duq. L. Rev.
Available at: https://dsc.duq.edu/dlr/vol5/iss1/8