diff --git a/compatibility/2.3.nom b/compatibility/2.3.nom
index 681ce89..a9c36a9 100644
--- a/compatibility/2.3.nom
+++ b/compatibility/2.3.nom
@@ -1,4 +1,7 @@
 #!/usr/bin/env nomsu -V2.5.4.3
+#
+    This file defines upgrades from Nomsu <2.3 to Nomsu 2.3
+
 use "compatibility/compatibility.nom"
 
 upgrade action (%a = %b) to "2.3" as (%a == %b)
diff --git a/compatibility/2.4.nom b/compatibility/2.4.nom
index 8a49e39..99f8c80 100644
--- a/compatibility/2.4.nom
+++ b/compatibility/2.4.nom
@@ -1,4 +1,7 @@
 #!/usr/bin/env nomsu -V2.5.4.3
+#
+    This file defines upgrades from Nomsu <2.4 to Nomsu 2.4
+
 use "compatibility/compatibility.nom"
 
 upgrade %tree to "2.4" as:
diff --git a/compatibility/2.5.nom b/compatibility/2.5.nom
index a67a28b..8816944 100644
--- a/compatibility/2.5.nom
+++ b/compatibility/2.5.nom
@@ -1,4 +1,7 @@
 #!/usr/bin/env nomsu -V2.5.4.3
+#
+    This file defines upgrades from Nomsu <2.5 to Nomsu 2.5
+
 use "compatibility/compatibility.nom"
 
 upgrade action (for %1 where %2 matches %3 %4) to "2.5" as (..)
diff --git a/compatibility/2.nom b/compatibility/2.nom
index 94517ea..13c65da 100644
--- a/compatibility/2.nom
+++ b/compatibility/2.nom
@@ -1,4 +1,7 @@
 #!/usr/bin/env nomsu -V2.5.4.3
+#
+    This file defines upgrades from Nomsu 1 to Nomsu 2
+
 use "compatibility/compatibility.nom"
 
 upgrade %tree to "2" as:
diff --git a/compatibility/compatibility.nom b/compatibility/compatibility.nom
index 6873e5e..001cd04 100644
--- a/compatibility/compatibility.nom
+++ b/compatibility/compatibility.nom
@@ -1,4 +1,8 @@
 #!/usr/bin/env nomsu -V2.5.4.3
+#
+    This file contains code for defining ways to upgrade code between different versions
+    of Nomsu.
+
 use "lib/os.nom"
 
 %UPGRADES = {}