diff --git a/README.md b/README.md
index e09b7a7..34ff307 100644
--- a/README.md
+++ b/README.md
@@ -358,6 +358,8 @@ to be good:
   shoots everything at whatever it is most likely to hit, and never thinks about
   heat. A bot that cannot beat it is not an improvement whatever it scores
   against Princess.
+- `bots/ineligible_bot.py` names a unit that does not exist in every decision,
+  to test that the host correctly refuses unit selections it cannot accept.
 
 ## Requirements