diff --git a/packages/marshal/src/encodePassable.js b/packages/marshal/src/encodePassable.js
index 387a88b402..bd4ff84cfb 100644
--- a/packages/marshal/src/encodePassable.js
+++ b/packages/marshal/src/encodePassable.js
@@ -98,6 +98,7 @@ const CanonicalNaNBits = 'fff8000000000000';
  */
 const encodeBinary64 = n => {
   // Normalize -0 to 0 and NaN to a canonical encoding
+  // TODO https://github.com/endojs/endo/issues/1602
   if (is(n, -0)) {
     n = 0;
   } else if (is(n, NaN)) {
diff --git a/packages/marshal/src/encodeToCapData.js b/packages/marshal/src/encodeToCapData.js
index 5546072a71..6fba569f66 100644
--- a/packages/marshal/src/encodeToCapData.js
+++ b/packages/marshal/src/encodeToCapData.js
@@ -149,6 +149,7 @@ export const makeEncodeToCapData = (encodeOptions = {}) => {
           return { [QCLASS]: '-Infinity' };
         }
         // Pass through everything else, replacing -0 with 0.
+        // TODO https://github.com/endojs/endo/issues/1602
         return is(passable, -0) ? 0 : passable;
       }
       case 'bigint': {
diff --git a/packages/marshal/src/encodeToSmallcaps.js b/packages/marshal/src/encodeToSmallcaps.js
index f96c51b841..a006148f14 100644
--- a/packages/marshal/src/encodeToSmallcaps.js
+++ b/packages/marshal/src/encodeToSmallcaps.js
@@ -204,6 +204,7 @@ export const makeEncodeToSmallcaps = (encodeOptions = {}) => {
           return '#-Infinity';
         }
         // Pass through everything else, replacing -0 with 0.
+        // TODO https://github.com/endojs/endo/issues/1602
         return is(passable, -0) ? 0 : passable;
       }
       case 'bigint': {
diff --git a/packages/marshal/src/rankOrder.js b/packages/marshal/src/rankOrder.js
index f8d8d9d95c..8d1dfccc11 100644
--- a/packages/marshal/src/rankOrder.js
+++ b/packages/marshal/src/rankOrder.js
@@ -36,6 +36,8 @@ const { entries, fromEntries, setPrototypeOf, is } = Object;
  * abstractions, where NaN is the same as NaN and -0 is the same as
  * 0. Marshal serializes -0 as zero, so the semantics of our distributed
  * object system does not distinguish 0 from -0.
+ * TODO https://github.com/endojs/endo/issues/1602
+ * and revise above comment.
  *
  * `sameValueZero` is the EcmaScript spec name for this equality comparison,
  * but TODO we need a better name for the API.