diff --git a/PRESUBMIT.py b/PRESUBMIT.py
index 343bd2968..ebd5c2f0e 100644
--- a/PRESUBMIT.py
+++ b/PRESUBMIT.py
@@ -12,11 +12,13 @@ import fnmatch
 import os
 
 
-ENSURE_FILE_TEMPLATE = r'''
-$VerifiedPlatform linux-amd64 linux-arm64 linux-armv6l linux-mips64
-$VerifiedPlatform linux-ppc64 linux-ppc64le linux-s390x
-$VerifiedPlatform mac-amd64
-$VerifiedPlatform windows-386 windows-amd64
+# CIPD ensure manifest for checking CIPD client itself.
+CIPD_CLIENT_ENSURE_FILE_TEMPLATE = r'''
+# Full supported.
+$VerifiedPlatform linux-amd64 mac-amd64 windows-amd64 windows-386
+# Best effort support.
+$VerifiedPlatform linux-386 linux-ppc64 linux-ppc64le linux-s390x
+$VerifiedPlatform linux-arm64 linux-armv6l linux-mips64
 
 %s %s
 '''
@@ -97,7 +99,8 @@ def CommonChecks(input_api, output_api, tests_to_black_list):
       pkg = 'infra/tools/cipd/${platform}'
       ver = input_api.ReadFile(path)
       tests.append(input_api.canned_checks.CheckCIPDManifest(
-          input_api, output_api, content=ENSURE_FILE_TEMPLATE % (pkg, ver)))
+          input_api, output_api,
+          content=CIPD_CLIENT_ENSURE_FILE_TEMPLATE % (pkg, ver)))
 
   results.extend(input_api.RunTests(tests))
   return results
diff --git a/cipd_manifest.txt b/cipd_manifest.txt
index 0268fc04e..3a17afc90 100644
--- a/cipd_manifest.txt
+++ b/cipd_manifest.txt
@@ -2,10 +2,14 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-$VerifiedPlatform linux-amd64 linux-arm64 linux-armv6l linux-mips64
-$VerifiedPlatform linux-ppc64 linux-ppc64le linux-s390x
-$VerifiedPlatform mac-amd64
-$VerifiedPlatform windows-386 windows-amd64
+# Fully supported plaforms.
+$VerifiedPlatform linux-amd64 mac-amd64 windows-amd64 windows-386
+
+# Platform with best-effort support: we have some binaries cross-compiled for
+# them, but we do not test they work. They also may not have all necessary
+# vpython packages.
+$VerifiedPlatform linux-386 linux-ppc64 linux-ppc64le linux-s390x
+$VerifiedPlatform linux-arm64 linux-armv6l linux-mips64
 
 # vpython.
 infra/tools/luci/vpython/${platform}  git_revision:4d19637ec2c3d1efd8c6a1b05285118b786919e2