a keystone is the last piece placed when building an arch. iirc (tho this anon isn't an architect), an arch is the most stable structure.
I'd be irritated, too, if a bunch of randos were doing to me what an awful lot of randos do, Re: "P".
Because I'm not a particularly bright Anon, just one who tends to archive a bunch of shit irl:
Is there a way for the archiveanons to collect the posts that don't have the trip, like in a separate box/thread/folder/file/whatevs, and and note in the "regular" archive that there are other posts that don't have trips and where they can be found?
Or read the news. Or Whitehouse.gov. Or listen to POTUS' words. Or any NUMBER of things that haven't exactly been top secret.
I like the way you think, Anon!