diff --git a/doc/tutorial/basics/emit.md b/doc/tutorial/basics/emit.md
index 7c8dd6e..03e25bf 100644
--- a/doc/tutorial/basics/emit.md
+++ b/doc/tutorial/basics/emit.md
@@ -6,6 +6,10 @@
 
 By default all top-level fields are emitted when evaluating a configuration.
 CUE files may define a top-level value that is emitted instead.
+<!-- jba:
+It's unclear how they do that. Is it the first form in the file?
+And this is not in the spec AFAICT.
+-->
 
 Values within the emit value may refer to fields defined outside of it.
 
@@ -28,4 +32,4 @@
 ```
 a: 1
 b: 2
-```
\ No newline at end of file
+```