CLN Operator · Reference
!
Bang
Risk · Warning · Blocker
"What can go wrong?"
Operator CLN v2.1 Plain-text · Universal
All operators =Equals .Dot !Bang ?Question →Arrow ~Tilde +Plus -Minus @At
01// ! — Definition

Warns. Flags danger. Marks blockers and edge cases.

Cognitive question answered: "What can go wrong?"
One line = one semantic unit. The Bang operator tells the reader — before they read the content — that this line answers: What can go wrong?
02// When to use it

Use ! for risks, warnings, critical caveats, blockers, or anything the reader must not miss. The eye finds ! before reading anything else.

When NOT to use it:
Don't use ! for general notes or observations — that's *. Don't inflate its use — ! means 'this matters urgently'.
03// Live Examples
Incident response
!503 on checkout — direct revenue impact — treat as P0
!prod bugs under real load — HIGH likelihood · rollback plan needed
!DB pool exhausted — check connection wait times immediately
Risk assessment
!competitor launch in same window — MEDIUM likelihood
!team stretched: dev + support + sales — simultaneous overload risk
!cash flow risk — sales cycle longer than forecast
Code review warning
!N+1 query on line 47 — will cause timeout at 100+ records
!no rate limiting on auth endpoint — brute force attack surface
!hardcoded secret in config.js — remove before merge
04// Operator Pairs

Operators don't work in isolation — they form semantic pairs that together convey full cognitive structure:

.! warns about a step · . defines the mitigation action
?! is a known risk · ? is an unverified hypothesis about a risk
~! is a concrete danger · ~ is an irresolvable structural tension