diff --git a/book/source/06-certifications.md b/book/source/06-certifications.md
index 327a521..2ff09ce 100644
--- a/book/source/06-certifications.md
+++ b/book/source/06-certifications.md
@@ -23,52 +23,7 @@ Signatures are the glue that allows for keys, subkeys and identities to be assem
 
 ## Terminology
 
-```{mermaid}
-
-%%{ init: { 'flowchart': { 'curve': '' } } }%%
-flowchart LR
-    signature(OpenPGP Signature)
-    3rdcert(Third-Party Certification)
-    data(Data Signature)
-    selfcert(Self Certification)
-    certification(Certification)
-
-    signature --> data & selfcert & 3rdcert & confsig & standalone & timestamp
-    data --> binary & text
-    selfcert --> skbind & skrev
-    selfcert & 3rdcert --> certification
-    certification --> uidcert & uidrev & dksig & krev
-    subgraph Siganture Types and Targets
-        standalone[0x02: Standalone]
-        subgraph Signature Packet
-            confsig[0x50: Third-Party Confirmation]
-            timestamp[0x40: Timestamp]
-        end
-        subgraph Data
-            binary[0x00: Binary Data]
-            text[0x01: Canonical Text]
-        end
-        subgraph Primary Key + User ID / Attr. Packet
-            uidcert[
-                0x10: Generic Certification
-                0x11: Persona Certification
-                0x12: Casual Certification
-                0x13: Positive Certification
-            ]
-            uidrev[0x30: Certification Revocation]
-        end
-        subgraph Primary Key
-            dksig[0x1F: Direct-Key Signature]
-            krev[0x20: Key Revocation]
-        end
-        subgraph Primary + Subkey
-            skbind[
-                0x18: Subkey Binding
-                0x19: Primary Key Binding
-            ]
-            skrev[0x28: Subkey Revocation]
-        end
-    end
+```{include} mermaid/06-terminology.md
 ```
 
 The term *signature* can have multiple meanings in the context of the OpenPGP specification.
diff --git a/book/source/mermaid/06-terminology.md b/book/source/mermaid/06-terminology.md
new file mode 100644
index 0000000..de1cd8c
--- /dev/null
+++ b/book/source/mermaid/06-terminology.md
@@ -0,0 +1,48 @@
+```{mermaid}
+
+%%{ init: { 'flowchart': { 'curve': '' } } }%%
+flowchart LR
+    signature(OpenPGP Signature)
+    3rdcert(Third-Party Certification)
+    data(Data Signature)
+    selfcert(Self Certification)
+    certification(Certification)
+
+    signature --> data & selfcert & 3rdcert & confsig & standalone & timestamp
+    data --> binary & text
+    selfcert --> skbind & skrev
+    selfcert & 3rdcert --> certification
+    certification --> uidcert & uidrev & dksig & krev
+    subgraph Siganture Types and Targets
+        standalone[0x02: Standalone]
+        subgraph Signature Packet
+            confsig[0x50: Third-Party Confirmation]
+            timestamp[0x40: Timestamp]
+        end
+        subgraph Data
+            binary[0x00: Binary Data]
+            text[0x01: Canonical Text]
+        end
+        subgraph Primary Key + User ID / Attr. Packet
+            uidcert[
+                0x10: Generic Certification
+                0x11: Persona Certification
+                0x12: Casual Certification
+                0x13: Positive Certification
+            ]
+            uidrev[0x30: Certification Revocation]
+        end
+        subgraph Primary Key
+            dksig[0x1F: Direct-Key Signature]
+            krev[0x20: Key Revocation]
+        end
+        subgraph Primary + Subkey
+            skbind[
+                0x18: Subkey Binding
+                0x19: Primary Key Binding
+            ]
+            skrev[0x28: Subkey Revocation]
+        end
+    end
+```
+