diff --git a/execution.bs b/execution.bs
index 32378f7..c2bdc35 100644
--- a/execution.bs
+++ b/execution.bs
@@ -6841,6 +6841,8 @@ enum class forward_progress_guarantee {
 
     2. <i>Synchronization:</i> This operation synchronizes with all `pop_front` operations on this object.
 
+    3. <i>Remarks:</i> If the thread of execution calling `run()` guarantees concurrent or parallel forward progress, then it guarantees parallel forward progress until `run()` returns; otherwise, it guarantees weakly parallel forward progress.
+
 ## Coroutine utilities <b>[exec.coro_utils]</b> ## {#spec-execution.coro_utils}
 
 ### `execution::as_awaitable` <b>[exec.as_awaitable]</b> ### {#spec-execution.coro_utils.as_awaitable}