Sacred Scripture as officially enumerated by the Council of Trent. Ecumenical councils which were truly universal in nature and authenticated by a successor of Peter. Other universally directed and authenticated papal teachings on matters of faith and morals . Papal stated intention when internally available is of great value. The whole area of direction, subject matter, and authentication is expected to require extensive development with the setting of parameters for proper understanding of various teachings.
All doctrine is infallible and as such is unchangeable.
Papal signature or perhaps the certifiable equivalent. Must be directed universally or the moral equivalent. Must cover matters of faith and morals. Non-infallible universally directed and authenticated papal teachings. A religious obedience in a unique way is to be given to the Holy Father even when he is not speaking ex cathedra.