Document NVM_SYMLINK_CURRENT env var from #514.
diff --git a/README.markdown b/README.markdown
index a239d6d..2c9e01a 100644
--- a/README.markdown
+++ b/README.markdown
@@ -79,6 +79,8 @@
 
     NVM_NODEJS_ORG_MIRROR=http://nodejs.org/dist nvm install 0.10
 
+`nvm use` will, by defaut, create a "current" symlink. Set `$NVM_SYMLINK_CURRENT` to any value other than "true" to disable this behavior.
+
 ## License
 
 nvm is released under the MIT license.