So if I understand what you are saying, your interpretation of Sola Scriptura is all (my word) Scripture is obvious?
A lot of folks claim Sola Scriptura, that is why I am asking your understanding of the Reformed formulation.
I think “the meaning is obvious (or the same because it is the same scripture) is one underlying assumption of sola scriptura.
I think when Luther discovered that this was not the case, interpretative catechisms/confessions became necessary. And this revealed a problem with sola sciptura - really, almost regardless of the specific definition.
So the logic of sola scriptura is violated if you need another document that says what doctrine you get from scripture in order to be of the Reformed faith.
thanks for your reply