diff --git a/README.md b/README.md
index 6fa5a2b..804e9f2 100644
--- a/README.md
+++ b/README.md
@@ -36,7 +36,7 @@ const showSplashScreen = response.settings?.showSplashScreen || true; // Potenti
 The nullary coalescing operator is intended to handle these cases better and serves as an equality check against nullary values (`null` or `undefined`). 
 
 ## Syntax
-*Base case*. If the expression at the left-hand side of the `??` operator evaluates to undefined or null, its right-hand side is returned.
+*Base case*. If the expression at the left-hand side of the `??:` operator evaluates to undefined or null, its right-hand side is returned.
 
 ```javascript
 const response = {
@@ -49,13 +49,17 @@ const response = {
   }
 };
 
-const undefinedValue = response.settings?.undefinedValue ?? 'some other default'; // result: 'some other default'
-const nullValue = response.settings?.nullValue ?? 'some other default'; // result: 'some other default'
-const headerText = response.settings?.headerText ?? 'Hello, world!'; // result: ''
-const animationDuration = response.settings?.animationDuration ?? 300; // result: 0
-const showSplashScreen = response.settings?.showSplashScreen ?? true; // result: false
+const undefinedValue = response.settings?.undefinedValue ??: 'some other default'; // result: 'some other default'
+const nullValue = response.settings?.nullValue ??: 'some other default'; // result: 'some other default'
+const headerText = response.settings?.headerText ??: 'Hello, world!'; // result: ''
+const animationDuration = response.settings?.animationDuration ??: 300; // result: 0
+const showSplashScreen = response.settings?.showSplashScreen ??: true; // result: false
 ```
 
+### Why the `??:` token?
+
+The initial proposal here used the token `??`, which is similar to what several other programming languages do for the same purpose. This proposal use `??:` instead, so that similar operators can be used by the [optional chaining proposal](https://github.com/TC39/proposal-optional-chaining) (e.g., `??[`). See [the past discussion](https://github.com/tc39/proposal-optional-chaining/issues/34) on this topic for more details.
+
 ## Notes
 While this proposal specifically calls out `null` and `undefined` values, the intent is to provide a complementary operator to the [optional chaining operator](https://github.com/TC39/proposal-optional-chaining). This proposal will update to match the sementics of that operator.
 
diff --git a/spec.html b/spec.html
index f31888b..84d6b58 100644
--- a/spec.html
+++ b/spec.html
@@ -8,11 +8,11 @@
 
 <emu-intro id=sec-intro>
   <h1>Introduction</h1>
-  <p>This document specifies the nullish coalescing operator `??`. See <a href="https://github.com/gisenberg/proposal-nullish-coalescing">the explainer</a> for an introduction.</p>
+  <p>This document specifies the nullish coalescing operator `??:`. See <a href="https://github.com/gisenberg/proposal-nullish-coalescing">the explainer</a> for an introduction.</p>
   <p>The main design decisions made in this specification are:
     <ol>
-      <li>The right argument of `??` is evaluated only if needed ("short circuiting").</li>
-      <li>`??` has the same precedence as `||`.</li>
+      <li>The right argument of `??:` is evaluated only if needed ("short circuiting").</li>
+      <li>`??:` has the same precedence as `||`.</li>
       <li>The right argument is selected if the left argument is `null` or `undefined`.</li>
     </ol>
   </p>
@@ -25,14 +25,14 @@ <h1>Syntax</h1>
       LogicalORExpression[In, Yield, Await] :
         LogicalANDExpression[?In, ?Yield, ?Await]
         LogicalORExpression[?In, ?Yield, ?Await] `||` LogicalANDExpression[?In, ?Yield, ?Await]
-        <ins>LogicalORExpression[?In, ?Yield, ?Await] `??` LogicalANDExpression[?In, ?Yield, ?Await]</ins>
+        <ins>LogicalORExpression[?In, ?Yield, ?Await] `??:` LogicalANDExpression[?In, ?Yield, ?Await]</ins>
   </emu-grammar>
 </emu-clause>
 
 <emu-clause id="sec-nullish-coalescing-evaluation">
   <h1>Runtime Semantics: Evaluation</h1>
 
-  <emu-grammar>LogicalORExpression : LogicalORExpression `??` LogicalANDExpression</emu-grammar>
+  <emu-grammar>LogicalORExpression : LogicalORExpression `??:` LogicalANDExpression</emu-grammar>
   <emu-alg>
     1. Let _lref_ be the result of evaluating |LogicalORExpression|.
     1. Let _lval_ be ? GetValue(_lref_).