Go to the "Off-Topic" or "Introductions" forum. Post something neutral: "Hello, longtime lurker, interested in game preservation. Rule 6 understood." This gives you the "1 post" needed to see hidden links.
Unfortunately, I don't have direct access to the subreddit's rules archive. However, I can tell you that Rule 6 of the r/CS subreddit currently states: "No low-effort posts. Posts should be thoughtful and engaging."
In the official "CS RIN Forum Rules" sticky, Rule 6 is deceptively short. Here is the exact text as it was enforced throughout 2021:
: It is closely tied to the search function—which notoriously requires at least 3 letters per word—forcing users to be precise and diligent before posting. Respect the "Clean"