Miniscript.

Would define Miniscript, a structured way to write Bitcoin's spending rules so software can check, combine and sign for them.

Bitcoin script, the small language that decides who can spend coins, is awkward and full of edge cases. Miniscript covers a useful part of it in a tidy form, so wallets can see what a script allows, combine conditions such as multisig and time locks, estimate what spending will cost, and produce the signatures it needs.