diff --git a/book/source/mermaid/06-terminology.md b/book/source/mermaid/06-terminology.md
index de1cd8c..4e49a41 100644
--- a/book/source/mermaid/06-terminology.md
+++ b/book/source/mermaid/06-terminology.md
@@ -1,12 +1,13 @@
 ```{mermaid}
-
 %%{ init: { 'flowchart': { 'curve': '' } } }%%
 flowchart LR
     signature(OpenPGP Signature)
     3rdcert(Third-Party Certification)
     data(Data Signature)
-    selfcert(Self Certification)
-    certification(Certification)
+    selfcert(Self-Signature)
+    certification("Third-Party Certification
+    --------------------------------
+    Self-Certification")
 
     signature --> data & selfcert & 3rdcert & confsig & standalone & timestamp
     data --> binary & text