diff --git a/README.md b/README.md
index f56df1e..acf810b 100644
--- a/README.md
+++ b/README.md
@@ -1,2 +1,7 @@
 # python-csr
-Generate a CSR/Key via Python
+# Generate a key, self-signed certificate, and certificate request.
+# Usage: csrgen <fqdn>
+# 
+# When more than one hostname is provided, a SAN (Subject Alternate Name)
+# certificate and request are generated.  This can be acheived by adding -s.
+# Usage: csrgen <hostname> -s <san0> <san1>