caveats

docs/caveats.md

+# Caveats
+
+Things to look out for
+
+
+## memoryviews
+
+Since CoolAMQP tries to be fast, it uses memoryviews everywhere. _ReceivedMessage_ objects, and message
+properties therefore, are memoryviews. So, it you wanted to read the routing key a message was sent with,
+or message's encoding, you should do:
+
+```python
+received_msg.routing_key.to_bytes()
+received_msg.properties.content_encoding.to_bytes()
+```
+
+Only the _body_ property of the message will be a byte object (and not even that it you set an option
+in Cluster.consume).
+