diff --git a/README.md b/README.md
index 851b46e1..b3975e2e 100644
--- a/README.md
+++ b/README.md
@@ -1417,6 +1417,38 @@ Other Style Guides
return name;
}
```
+
+ - [13.5](#variables--no-chain-assignment) Don't chain variable assignments. eslint: [`one-var`](http://eslint.org/docs/rules/one-var.html)
+
+ > Why? Chaining variable assignments creates implicit global variables.
+
+ ```javascript
+ // bad
+ (function example() {
+ // JavaScript interprets this as
+ // let a = ( b = ( c = 1 ) );
+ // The let keyword only applies to variable a; variables b and c become
+ // global variables.
+ let a = b = c = 1;
+ }());
+
+ console.log(a); // undefined
+ console.log(b); // 1
+ console.log(c); // 1
+
+ // good
+ (function example() {
+ let a = 1;
+ let b = a;
+ let c = a;
+ }());
+
+ console.log(a); // undefined
+ console.log(b); // undefined
+ console.log(c); // undefined
+
+ // the same applies for `const`
+ ```
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