From d30822a6fbf9e0a41e58c41f36802e8da094d57f Mon Sep 17 00:00:00 2001
From: Tiziano Perrucci <tiziano.perrucci@gmail.com>
Date: Thu, 25 Apr 2019 16:52:42 +0200
Subject: [PATCH] readme: add legacy support section

---
 README.rst | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/README.rst b/README.rst
index 37efc207..52bcf325 100644
--- a/README.rst
+++ b/README.rst
@@ -42,6 +42,19 @@ Packages are also uploaded to Anaconda Cloud at
 https://anaconda.org/indygreg/zstandard. See that URL for how to install
 this package with ``conda``.
 
+Legacy Format Support
+=====================
+
+To enable legacy zstd format support which is needed to handle files compressed
+with zstd < 1.0 you need to provide an installation option::
+
+   $ pip install zstandard --install-option="--legacy"
+
+and since pip 7.0 it is possible to have the following line in your
+requirements.txt::
+
+   zstandard --install-option="--legacy"
+
 Performance
 ===========