So here it is — the closest thing to an index of those shapes. Not a real index. A guided one: I'll walk you over to a few and leave the rest on the shelf.

They sort, loosely, into a handful of families — some are about flows and gradients, some about bottlenecks, some about how a record forms, some about how constraints pile up, some about things getting compressed. You don't need the shelving. What's worth your time is a few of the shapes themselves, ones we haven't already handled.

You already met a bottleneck — the diamond's. That one happened to the carbon, with nobody arranging it. Here's the other kind: the bottleneck somebody built on purpose. A hiring funnel. A stack of résumés at the top; a screen cuts it to a handful; a phone call cuts the handful to a few; an interview cuts it to one. Every stage is a gate, set deliberately, to let less and less through. That's a Designed BottleneckA named pattern in the catalog: the engineered counterpart to the diamond's natural bottleneck — a funnel somebody built on purpose, gate after gate set to let less through. — the same shape as the diamond, but engineered — and once you've named it you start seeing it everywhere: auditions, visa lines, the turnstile at a show.

Here's one with a sense of humor. Watch what happens to a system when you keep fixing it. A law gets a patch to close a loophole; the patch has its own loophole, so it gets a patch; the patches grow patches. Tax codes do this. Old software does this. Give it long enough and the patches are the system, the thing they were protecting is buried somewhere underneath, and nobody can fix it anymore because nobody can find it. That's Patch AccumulationA named pattern: a record of every fix, stacked until the stack itself is the system — the same shape found across software, law, and biology. — a record of every fix ever made, stacked until the stack becomes the problem.

And one that runs the other way — not piling up, but crushing down. A whole tangled situation collapsed into a single figure. A price is one: everything about supply and scarcity and want and mood, squeezed down to one number you can read at a glance. A diagnosis is another — a person's whole messy chart pressed into a single word. That's a CompressionA named pattern: a whole tangled situation crushed to one figure you can act on — a record at maximum tightness.: a record at its very tightest, almost nothing left but the part that lets you act.

Three shapes, three of the families. There are more on the shelf, and you can feel how the game goes now — you carry one of these over to something you already know, and you check whether it fits.

But a guided index is only worth trusting if someone's been honest about what didn't make the shelf. So let me show you that part.