The rare exceptions are that the Catholic Church doesn't recognize baptism by the Moonies, JW's, Unitarians, or Mormons. The reason why, is that their doctrine about who Christ is differs radically from the understanding of historic, Biblical Christianity.
Excellent and true, Mrs. Don-o. That’s my entire point. The Protestants are schismatic Catholics, thus the Catholic church recognizes their baptisms (when they still do that), even though they don’t have a priesthood or that they don’t see baptism as a sacrament.
The only thing, and it’s not trifling, is that the reason is not Biblical, but one of interpretation. Keep in mind that with the same vigor Catholics embrace, the Reformers reject. I remember the good old days when every Protestant knew that Catholics aren’t Christians and are doomed to hell.
Nostalgia...there really weren’t any good old days were there?