diff --git a/book/source/06-signatures.md b/book/source/06-signatures.md
index 16b5e1c..946d513 100644
--- a/book/source/06-signatures.md
+++ b/book/source/06-signatures.md
@@ -43,12 +43,6 @@ Signature on components are a complex topic, which we discuss in depth in {ref}`
 An overview of signature types in OpenPGP
 ```
 
-```{admonition} TODO
-:class: warning
-
-Group "Third-Party Certification" and "Self-Signature" as "Signature on components", in the diagram?
-```
-
 In this chapter we discuss general principles, which apply to all types of OpenPGP signatures.
 
 For more detail about specific types of signatures, see the chapters {ref}`signing_data` and {ref}`component_signatures_chapter`, respectively.