diff --git a/core/modules/file/migration_templates/d6_file.yml b/core/modules/file/migration_templates/d6_file.yml
index 0fdcd84..6df20b5 100644
--- a/core/modules/file/migration_templates/d6_file.yml
+++ b/core/modules/file/migration_templates/d6_file.yml
@@ -13,6 +13,9 @@ source:
     # configuration in this migration's process pipeline as an example.
     source_base_path: ''
 process:
+    # If you are using both this migration and d6_user_picture_file in a custom
+    # migration and executing migrations incrementally, it is recommended that
+    # you remove the fid mapping here to avoid potential ID conflicts.
   fid: fid
   filename: filename
   source_full_path:
diff --git a/core/modules/user/migration_templates/d6_user_picture_file.yml b/core/modules/user/migration_templates/d6_user_picture_file.yml
index 3518d7a..d367f33 100644
--- a/core/modules/user/migration_templates/d6_user_picture_file.yml
+++ b/core/modules/user/migration_templates/d6_user_picture_file.yml
@@ -11,6 +11,9 @@ source:
     # table are specified, and must end with a /.
     source_base_path: ''
 process:
+    # If you are using both this migration and d6_file in a custom migration
+    # and executing migrations incrementally, it is recommended that you
+    # remove the fid mapping from d6_file to avoid potential ID conflicts.
   filename: filename
   uid: uid
   source_full_path: