The reason for the House Rule in last week's post will become increasingly clear as I go on about the curation process.
This week, we're going to look at what curation in RIFTS means. RIFTS is a game with a lot of sub-settings, much like HERO has its various genre books that sub-divide into major variations of those genres and then go on to address specific iterations and how the tropes and themes work. RIFTS deals with the same concept by marking out space in a given section of the setting and reserving it for that sort of genre or sub-genre. (E.g. "Cosmic Heroes" and "Space Opera" are the realm of the Three Galaxies sub-setting.)
Curation, therefore, must be done first to answer what sort of campaign you want to run. Take all that you own, and cut away every last bit that does not fit what you want. A campaign built around being Coalition Grunts slogging through yet another military campaign has no place for options and content that said Grunts will not encounter. Players should not access anything that doesn't fit that campaign's intention- not species or races, not Occupations, not gear, not powers, nothing at all.
So, the rule: "Players may not access options or content contrary to the campaign's premise."
This is, again, about pairing down all of the massive amount of stuff out there into something that you can easily and readily manage at the table; if you're playing the command crew of a specific starship, then you don't need to allow options to be or use anything else.