diff --git a/README.md b/README.md
index 469e26d..41094b2 100644
--- a/README.md
+++ b/README.md
@@ -4,6 +4,10 @@
 * `0.14.20`, `stable` [(0.14/Dockerfile)](https://github.com/dtandersen/docker_factorio_server/blob/0.14.20/0.14/Dockerfile)
 * `0.13.20`, `0.13`  [(0.13/Dockerfile)](https://github.com/dtandersen/docker_factorio_server/blob/master/0.13/Dockerfile)
 
+* `latest` - highest version: may be experimental.
+* `stable` - highest version declared stable.
+* `0.x` - highest version of factorio in that branch: may be experimental.
+
 # What is Factorio?
 
 [Factorio](https://www.factorio.com) is a game in which you build and maintain factories.