What does "authentic magisterium" entail in Lumen Gentium?

Lumen Gentium 25 states in part: >In matters of faith and morals, the bishops speak in the name of Christ and the faithful are to accept their teaching and adhere to it with a religious assent (*religioso animi obsequio* ). This religious submission of mind and will (*religiosum voluntatis et intellectus obsequium* ) must be shown in a special way to the authentic magisterium (*authentico magisterio* ) of the Roman Pontiff What is the scope of the authentic magisterium of the Pope? How does this differ from the Ordinary or Extraordinary Magisterium of the Church? Can the authentic Magisterium of the Roman Pontiff conflict with the general Magisterium (what has been taught previously)? Is the Roman Pontiff the specific current holder or the general office?