With divine inspiration, the First Presidency (the prophet and his two counselors) and the Quorum of the Twelve Apostles (the second-highest governing body of the Church) counsel together to establish doctrine that is consistently proclaimed in official Church publications. This doctrine resides in the four “standard works” of scripture (the Holy Bible, the Book of Mormon, the Doctrine and Covenants and the Pearl of Great Price), official declarations and proclamations, and the Articles of Faith.
I think this is saying that the Doctrine itself is contained within:
The four standard works - Bible, Book of Mormon, Doctrine & Covenants and The Pearl of Great Price.
Official Declarations - published at the end of the D&C
Official Proclamations - e.g. Proclamation on The Family
The Articles Of Faith
Everything else published by the Church (Ensign, books, teaching manuals etc) is not doctrine but may be commentary and teaching on doctrine.
I hope this doesn't come across as splitting hairs but I feel it is an important distinction.
It's not how the Church sees it.
Notice that the doctrine is established by the FP and Qo12, and then published. However, it merely resides in the Standard Works etc. BEFORE it is established. Neither you or I is qualified or authorized to open the scriptures, point to a verse, and state authoritatively that such and such is the official LDS doctrine on that verse.
I call it the John 3:5 problem. What does the water refer to in that verse? To an EV and most other Protestants, it means physical birth. To an LDS person, it means water baptism. How does the LDS person know that? From some official publication or another. Without the published doctrine, an LDS person might guess baptism or might go along with the EV as to the interpretation.
What good are the scriptures if they are not interpreted correctly by those authorized by God (2 Peter 1:20, Ephesians 4:11-14, etc.)? Hence, we have the Restoration..... And therefore,
the published doctrine is more important than scripture because it contains the official position of the Church.