diff --git a/docs/api-guide/throttling.md b/docs/api-guide/throttling.md
index c157e1ecd..1ca146b51 100644
--- a/docs/api-guide/throttling.md
+++ b/docs/api-guide/throttling.md
@@ -222,6 +222,8 @@ Using `get_debounce_interval()`, one can e.g. ensure superusers can always invok
                 return 0
             return 5
 
+Note that due to the current implementation, debouncing _requires_ a throttling rate to be set as well.
+
 [cite]: https://developer.twitter.com/en/docs/basics/rate-limiting
 [permissions]: permissions.md
 [identifying-clients]: http://oxpedia.org/wiki/index.php?title=AppSuite:Grizzly#Multiple_Proxies_in_front_of_the_cluster
diff --git a/rest_framework/throttling.py b/rest_framework/throttling.py
index dc2cde30c..bc1ca853e 100644
--- a/rest_framework/throttling.py
+++ b/rest_framework/throttling.py
@@ -67,6 +67,9 @@ class SimpleRateThrottle(BaseThrottle):
     debounce_interval = None
 
     def __init__(self):
+        # TODO: this should probably be deferred to `allow_request`,
+        #       to simplify `ScopedRateThrottle` as well as to allow debouncing
+        #       without rate limiting.
         if not getattr(self, 'rate', None):
             self.rate = self.get_rate()
         self.num_requests, self.duration = self.parse_rate(self.rate)