diff --git a/src/Model/Types/Common.hs b/src/Model/Types/Common.hs
index ae8f79f83..5ffbcfb07 100644
--- a/src/Model/Types/Common.hs
+++ b/src/Model/Types/Common.hs
@@ -1,3 +1,9 @@
+{-|
+Module: Model.Types.Common
+Description: Common types used by most @Model.Types.*@-Modules
+
+Types used by multiple other @Model.Types.*@-Modules
+-}
 module Model.Types.Common
   ( module Model.Types.Common
   ) where
diff --git a/src/Model/Types/Course.hs b/src/Model/Types/Course.hs
index ca619a77a..4a1a08b3c 100644
--- a/src/Model/Types/Course.hs
+++ b/src/Model/Types/Course.hs
@@ -1,3 +1,9 @@
+{-|
+Module: Model.Types.Course
+Description: Types for modeling Courses
+
+Also see `Model.Types.Sheet`
+-}
 module Model.Types.Course
   ( module Model.Types.Course
   ) where
diff --git a/src/Model/Types/DateTime.hs b/src/Model/Types/DateTime.hs
index 795647003..10783550e 100644
--- a/src/Model/Types/DateTime.hs
+++ b/src/Model/Types/DateTime.hs
@@ -1,3 +1,9 @@
+{-|
+Module: Model.Types.DateTime
+Description: Time related types
+
+Terms, Seasons, and Occurence schedules
+-}
 module Model.Types.DateTime
   ( module Model.Types.DateTime
   ) where
@@ -58,6 +64,7 @@ instance Enum TermIdentifier where
 -- from_TermIdentifier_to_TermId = TermKey
 
 shortened :: Iso' Integer Integer
+-- ^ Year numbers shortened to two digits
 shortened = iso shorten expand
   where
     century = ($currentYear `div` 100) * 100
diff --git a/src/Model/Types/Exam.hs b/src/Model/Types/Exam.hs
index f037ce79b..fb7ed10a1 100644
--- a/src/Model/Types/Exam.hs
+++ b/src/Model/Types/Exam.hs
@@ -1,3 +1,7 @@
+{-|
+Module: Model.Types.Exam
+Description: Types for modeling Exams
+-}
 module Model.Types.Exam
   ( module Model.Types.Exam
   ) where
diff --git a/src/Model/Types/Health.hs b/src/Model/Types/Health.hs
index 788ca54f7..aea99d735 100644
--- a/src/Model/Types/Health.hs
+++ b/src/Model/Types/Health.hs
@@ -1,3 +1,7 @@
+{-|
+Module: Model.Types.Health
+Description: Types for running self-tests
+-}
 module Model.Types.Health
   ( module Model.Types.Health
   ) where
diff --git a/src/Model/Types/Mail.hs b/src/Model/Types/Mail.hs
index 5aeb1d14a..d2507e6f9 100644
--- a/src/Model/Types/Mail.hs
+++ b/src/Model/Types/Mail.hs
@@ -1,6 +1,11 @@
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE UndecidableInstances #-}
 
+{-|
+Module: Model.Types.Mail
+Description: Types related to Notifications
+-}
+
 module Model.Types.Mail
   ( module Model.Types.Mail
   ) where
diff --git a/src/Model/Types/Misc.hs b/src/Model/Types/Misc.hs
index 8d45e6798..efe0308a6 100644
--- a/src/Model/Types/Misc.hs
+++ b/src/Model/Types/Misc.hs
@@ -1,3 +1,8 @@
+{-|
+Module: Model.Types.Misc
+Description: Additional uncategorized types
+-}
+
 module Model.Types.Misc
   ( module Model.Types.Misc
   ) where
diff --git a/src/Model/Types/Security.hs b/src/Model/Types/Security.hs
index cba46f371..1c1919fdf 100644
--- a/src/Model/Types/Security.hs
+++ b/src/Model/Types/Security.hs
@@ -1,5 +1,10 @@
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
 
+{-|
+Module: Model.Types.Security
+Description: Types for authentication and authorisation
+-}
+
 module Model.Types.Security
   ( module Model.Types.Security
   ) where
diff --git a/src/Model/Types/Sheet.hs b/src/Model/Types/Sheet.hs
index 961ea7400..74fb91dc1 100644
--- a/src/Model/Types/Sheet.hs
+++ b/src/Model/Types/Sheet.hs
@@ -1,3 +1,8 @@
+{-|
+Module: Model.Types.Sheet
+Description: Types for modeling sheets
+-}
+
 module Model.Types.Sheet
   ( module Model.Types.Sheet
   ) where
diff --git a/src/Model/Types/Submission.hs b/src/Model/Types/Submission.hs
index c70919195..c31fa38fc 100644
--- a/src/Model/Types/Submission.hs
+++ b/src/Model/Types/Submission.hs
@@ -1,5 +1,10 @@
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
 
+{-|
+Module: Model.Types.Submission
+Description: Types to support sheet submissions
+-}
+
 module Model.Types.Submission
   ( module Model.Types.Submission
   ) where