diff --git a/packages/integration-testsuite/src/apolloServerTests.ts b/packages/integration-testsuite/src/apolloServerTests.ts
index fd7fcfb3c41..796f46ef0e2 100644
--- a/packages/integration-testsuite/src/apolloServerTests.ts
+++ b/packages/integration-testsuite/src/apolloServerTests.ts
@@ -2154,6 +2154,8 @@ export function defineIntegrationTestSuiteApolloServerTests(
     });
 
     describe('usage reporting', () => {
+      // FIXME ensure deferred fields get usage-reported
+
       async function makeFakeUsageReportingServer({
         status,
         waitWriteResponse = false,
diff --git a/packages/server/src/externalTypes/incrementalDeliveryPolyfill.ts b/packages/server/src/externalTypes/incrementalDeliveryPolyfill.ts
index 8aeac2f1a61..7052408c0fc 100644
--- a/packages/server/src/externalTypes/incrementalDeliveryPolyfill.ts
+++ b/packages/server/src/externalTypes/incrementalDeliveryPolyfill.ts
@@ -1,6 +1,11 @@
 import type { FormattedExecutionResult, GraphQLFormattedError } from 'graphql';
 
-// FIXME explain this file
+// This file defines types used in our public interface that will be imported
+// from `graphql-js` once graphql 17 is released. It is possible that these
+// types will change slightly before the final v17 is released, in which case
+// the relevant parts of our API may change incompatibly in a minor version of
+// AS4; this should not affect any users who aren't explicitly installing
+// pre-releases of graphql 17.
 
 interface ObjMap<T> {
   [key: string]: T;
diff --git a/packages/server/src/incrementalDeliveryPolyfill.ts b/packages/server/src/incrementalDeliveryPolyfill.ts
index 6fc0351f50a..4c8b7afcc47 100644
--- a/packages/server/src/incrementalDeliveryPolyfill.ts
+++ b/packages/server/src/incrementalDeliveryPolyfill.ts
@@ -1,6 +1,9 @@
 import { execute, ExecutionArgs, ExecutionResult, GraphQLError } from 'graphql';
 
-// FIXME explain this file
+// This file "polyfills" graphql@17's experimentalExecuteIncrementally (by
+// returning a function that does not understand incremental directives if
+// you're using graphql@16). The types defined in this file are largely copied
+// from graphql-js.
 
 interface ObjMap<T> {
   [key: string]: T;
@@ -70,7 +73,10 @@ export interface GraphQLExperimentalIncrementalExecutionResults<
 
 type PromiseOrValue<T> = Promise<T> | T;
 
-// FIXME doc the tristate
+// This starts as undefined and is set to a function or null by running
+// tryToLoadGraphQL17(). If graphql-js 17 is installed, it is set to the
+// experimentalExecuteIncrementally function from that package; otherwise it is
+// set to null.
 let graphqlExperimentalExecuteIncrementally:
   | ((
       args: ExecutionArgs,
diff --git a/smoke-test/smoke-test.sh b/smoke-test/smoke-test.sh
index 174065c0a62..73ede55bf1c 100755
--- a/smoke-test/smoke-test.sh
+++ b/smoke-test/smoke-test.sh
@@ -37,4 +37,3 @@ tsc --build tsconfig.{esm,cjs}.json
 node generated/tsc/smoke-test.cjs
 node generated/tsc/smoke-test.mjs
 
-# FIXME if INCREMENTAL_DELIVERY_TESTS_ENABLED is set, run an incremental delivery test.