I hear often the argument that the Council of Vatican II was not infallible and can be resisted when teaching an error on faith and morals that conflicts with Tradition. This argument is based on the premise that there is a third level of teaching that belongs to the Ordinary Magisterium, is universal, but yet is not infallible like the second level of teaching that belongs to the same Universal Ordinary Magisterium. This is due to the supposed lack of language within the teaching and the lack of an anathema if rejected. See here, here and here for such an argument.
In my studies, I have yet to find any Church teaching, prior to Vatican II, mentioning this third level of teaching. Those who subscribe to this idea try to prove their position to be true by quoting Vatican II popes or more recent ones. This presents a problem because one must accept a post Vatican II teaching in order to deny others. It also seems that this third level of teaching was introduced to us by Modernists who reject early 1900s PBC declarations and other teachings such as those in Casti Connubii, Humani Generis and adopted by those who reject Humanae Vitae. This position has also been conveniently adopted by Traditionalists in order to reject Vatican II and its universal novel teachings on faith and morals.
Can anyone provide me with authoritative teachings of the Church prior to 1962 that will either prove true this third level of teaching or prove it to be a myth?