diff --git a/docs/asgi.rst b/docs/asgi.rst
index 61c0cfa..c7dbcd8 100644
--- a/docs/asgi.rst
+++ b/docs/asgi.rst
@@ -413,11 +413,17 @@ main response, and you should check for ``http_version = 2`` before sending
 them; if a protocol server or connection incapable of Server Push receives
 these, it should simply drop them.
 
-The HTTP specs are somewhat vague on the subject of multiple headers;
-RFC7230 explicitly says they must be merge-able with commas, while RFC6265
-says that ``Set-Cookie`` headers cannot be combined this way. This is why
-request ``headers`` is a ``dict``, and response ``headers`` is a list of
-tuples, which matches WSGI.
+Multiple header fields with the same name are complex in HTTP. RFC 7230
+states that for any header field that can appear multiple times, it is exactly
+equivalent to sending that header field only once with all the values joined by
+commas.
+
+However, RFC 7230 and RFC 6265 make it clear that this rule does not apply to
+the various headers used by HTTP cookies (``Cookie`` and ``Set-Cookie``). The
+``Cookie`` header must only be sent once by a user-agent, but the
+``Set-Cookie`` header may appear repeatedly and cannot be joined by commas.
+For this reason, we can safely make the request ``headers`` a ``dict``, but
+the response ``headers`` must be sent as a list of tuples, which matches WSGI.
 
 Request
 '''''''