 README.md | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 5d1c90f..f863b59 100644
--- a/README.md
+++ b/README.md
@@ -39,7 +39,9 @@ There is no detailed documentation about BigPipe yet, but all of the following d
 
 - BigPipe uses streaming, this means any proxy in between should not buffer the response: the origin needs to stream directly to the end user.
 - Hence the web server and any proxies should not buffer the response, or otherwise the end result is still a single flush, which means worse performance again.
-- BigPipe responses contain the header `Surrogate-Control: no-store, content="BigPipe/1.0"`.
+- BigPipe responses contain the header `Surrogate-Control: no-store, content="BigPipe/1.0"`. For more information about this header, see <https://www.w3.org/TR/edge-arch/>.
+
+Note that this version number (`BigPipe/1.0`) is not expected to increase, since all that is necessary for a proxy to support BigPipe, is the absence of buffering. No additional proxy requirements are expected to ever be added.
 
 
 ## Apache
