I think there are three ways in which the wording of this ruling could be improved:
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It seems to me that it only applies to events and operations. Cards of other types often don’t have any immediate effect when installed. They only change the game state by decreasing the amount of credits a player has, leaving his hand, and being installed in the “in play” zone. If this is considered to be enough of a game state change, I’m not sure why an event/operation leaving a player’s hand and going to the heap/archives is not (e.g. Archived Memories with no cards in Archives). I suggest the following wording: “A player can only play an event/opertion or trigger an ability if…”
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The second sentence should cover trigger costs (for paid abilities, and some conditional abilities).
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The second sentence should explicitly mention additional costs, because currently the game vocabulary is quite obscure about the difference between “all play/install/rez costs” and singular “play/install/rez cost”.