The Grammar of Bitcoin's Extensibility

The Upgrade-Slot Explorer · 升级插槽浏览器

Bitcoin doesn't add a feature by inventing a new byte. It reserves slots in advance, then fills them. Pick a proposal below and watch — on real signet bytes — which reserved slot it plugs into, and why the block explorer still shows it under its pre-activation name.

Pick a proposal (real on-chain leaf)

The real bytes

the address (scriptPubKey) — the identical 5120… shape on every card:

Which slot does it plug into?

The dramatic reveal — same byte, before vs after the soft fork

before activation
after activation

The slot inventory — how many unopened slots is Bitcoin still holding?

Count them: reserved-but-empty upgrade slots. Every future soft fork has to fit one of these shapes — or add a brand-new one. That is the grammar of Bitcoin's extensibility.
Every byte here is from Aaron's real signet transactions (see the artifact ledger). Companion to the booklet and the sighash playground.