diff --git a/FEDERATION.md b/FEDERATION.md
index d43b14c..87bb2b5 100644
--- a/FEDERATION.md
+++ b/FEDERATION.md
@@ -466,6 +466,8 @@ Requirements, suggestions and details:
 
 TODO:
 
+- `followers` is for actors, it seems, by the AP spec? So, what do we call the
+  collection of followers of a ticket?
 - `replies` and how the C2S object nesting depth proposal
 - Use `nonActors` in the example?
 - Content format? HTML? Markdown source? Tags? Referenced ticktes?