diff --git a/BlogClient.markdown b/BlogClient.markdown
index fa36a33..576af63 100644
--- a/BlogClient.markdown
+++ b/BlogClient.markdown
@@ -7,7 +7,7 @@ BlogClient uses the following client identifer:
 
 Each blog has its own channel, and there is a single invitation channel shared by all blogs. The [channel descriptor](BSP#channel-identifiers) for the invitation channel is an empty [BDF list](BDF).
 
-The channel descriptor for a blog channel is a list with two elements: `title` (string) and `public_key` (raw).
+The descriptor for a blog channel is a list with two elements: `title` (string) and `public_key` (raw). Posts are signed with the corresponding private key.
 
 ### Message types