diff --git a/README.md b/README.md
index 4342cd0..685d17b 100644
--- a/README.md
+++ b/README.md
@@ -8,3 +8,8 @@ relies on [EnTT](https://github.com/skypjack/entt)
 
 When adding a new contact, make sure to check for existing contacts of the same `ID` component first and merge into it instead.
 
+## Implementer checklist:
+
+- Make sure there is a root node
+- every node, except the root node, needs to have a parent (a tree if only going up)
+