options: reserved extension range for CSI
diff --git a/docs/options.md b/docs/options.md
index 700fef6..9604dd5 100644
--- a/docs/options.md
+++ b/docs/options.md
@@ -193,4 +193,7 @@
    * Website: https://bitbucket.org/ooicgsn/cgsn-mooring
    * Extensions: 1058
    
+1. Container Storage Interface
+   * Website: https://github.com/container-storage-interface/spec
+   * Extensions: 1059-1069