diff --git a/README.md b/README.md
index 4f48bd1..f62c408 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,10 @@
 # Tinc upload role
 
 Synchronizes a set of known hosts to a tinc node.
+
+This synchronizes a set of tinc host files (fetched with the tinc
+role or by hand, into fetch/) to a remote host.
+
+# Expected group vars
+
+* **netname**: Tinc network name