Verdi's great opera Don Carlo(s), by far his most ambitious work, went through many revisions, starting with the excision of some music during rehearsals at the Opera de Paris. The composer prepared additional performing versions of the score; sometimes it is presented in French, sometimes in Italian.
For your preseason research pleasure, I asked San Francisco Opera which version they'd be performing. It is the five-act Modena version of 1886. It includes the Fontainebleau scene, but not the scene where Elisabetta and Eboli change veils, which explains the subsequent scene where Carlo mistakes Eboli for Elisabetta. You can read the official synopsis on the SFO web site.
(I am reasonably sure that at some point SFO presented a version that included the scene in the Fontainebleau act with Elisabetta and the woodcutters, but who knows? I may be making this up. It was one of the pre-premiere cuts that Verdi himself made.)