diff --git a/src/Database/Esqueleto/Utils.hs b/src/Database/Esqueleto/Utils.hs
index 152d506ae..9c09b41f9 100644
--- a/src/Database/Esqueleto/Utils.hs
+++ b/src/Database/Esqueleto/Utils.hs
@@ -280,7 +280,8 @@ subSelectOr  q = parens . E.subSelectUnsafe $ flip (E.unsafeSqlAggregateFunction
 parens :: E.SqlExpr (E.Value a) -> E.SqlExpr (E.Value a)
 parens = E.unsafeSqlFunction ""
 
--- | Workaround for Esqueleto-Bug not placing parenthesis after NOT, see #155
+-- | Workaround for Esqueleto-Bug not placing parenthesis after NOT.
+--   This leads to erroneous filters. For examples, see DevOps #1970
 not__ :: E.SqlExpr (E.Value Bool) -> E.SqlExpr (E.Value Bool)
 not__ = E.not_ . parens
 
diff --git a/src/Handler/Course/Edit.hs b/src/Handler/Course/Edit.hs
index 1e06c919b..17fe34a67 100644
--- a/src/Handler/Course/Edit.hs
+++ b/src/Handler/Course/Edit.hs
@@ -70,7 +70,7 @@ courseToForm (Entity cid Course{..}) lecs lecInvites qualis = CourseForm
     , cfDeRegUntil          = courseDeregisterUntil
     , cfLecturers           = [Right (lecturerUser, lecturerType) | Lecturer{..} <- lecs]
                            ++ [Left (email, mType) | (email, InvDBDataLecturer mType) <- Map.toList lecInvites ]
-    -- TODO: Filterung nach aktueller Schule, da ansonsten ein Sicherheitleck droht! Siehe #150
+    -- TODO: Filterung nach aktueller Schule, da ansonsten ein Sicherheitleck droht! Siehe auch DevOps #1878
     , cfQualis              = [ (courseQualificationQualification, courseQualificationSortOrder)
                               | CourseQualification{..} <- qualis, courseQualificationCourse == cid ]
     }
@@ -471,7 +471,7 @@ upsertCourseQualifications uid cid qualis = do
   let newQualis = Map.fromList qualis
   oldQualis <- Map.fromList . fmap (\Entity{entityKey=k, entityVal=CourseQualification{..}} -> (courseQualificationQualification, (k, courseQualificationSortOrder)))
                 <$> selectList [CourseQualificationCourse ==. cid] [Asc CourseQualificationQualification]
-  -- NOTE: CourseQualification allow the immediate assignment of these qualifications to any enrolled user. Hence SchoolAdmins must not be allowed to assign school-foreign qualifications, see #150
+  -- NOTE: CourseQualification allow the immediate assignment of these qualifications to any enrolled user. Hence SchoolAdmins must not be allowed to assign school-foreign qualifications here! Also see DevOps #1878
   okSchools <- Set.fromList . fmap (userFunctionSchool . entityVal)
                 <$> selectList [UserFunctionUser ==. uid, UserFunctionFunction <-. [SchoolAdmin, SchoolLecturer]] [Asc UserFunctionSchool]
   {- Some debugging due to an error caused by using fromDistinctAscList with violated precondition:
diff --git a/src/Handler/Health/Interface.hs b/src/Handler/Health/Interface.hs
index 58cfcbe4a..e19945f1b 100644
--- a/src/Handler/Health/Interface.hs
+++ b/src/Handler/Health/Interface.hs
@@ -150,7 +150,7 @@ mkInterfaceLogTable interfs@(reqIfs, banIfs) = do
            ]
       unless (null reqIfs) $ E.where_ $ matchUIH    reqIfs
       unless (null banIfs) $ E.where_ $ matchUIHnot banIfs
-      -- unless (null banIfs) $ E.where_ $ E.not_ $ matchUIH banIfs -- !!! DOES NOT WORK !!! Yields strange results, see #155
+      -- unless (null banIfs) $ E.where_ $ E.not_ $ matchUIH banIfs -- !!! DOES NOT WORK !!! Yields strange results, see DevOps #1970
       -- unless (null banIfs) $ E.where_ $ E.not_ $ E.parens $ matchUIH banIfs -- WORKS OKAY
       -- E.where_ $ E.not_ (ilog E.^. InterfaceLogInterface E.==. E.val "LMS" E.&&.  ilog E.^. InterfaceLogSubtype E.==. E.val (sanitize "F")) -- BAD  All missing, except for "Printer" "F"
       -- E.where_ $ E.not_ $ E.parens (ilog E.^. InterfaceLogInterface E.==. E.val "LMS" E.&&.  ilog E.^. InterfaceLogSubtype E.==. E.val (sanitize "F")) -- WORKS OKAY
diff --git a/src/Utils.hs b/src/Utils.hs
index ff0a98212..4f20248d3 100644
--- a/src/Utils.hs
+++ b/src/Utils.hs
@@ -967,12 +967,13 @@ whenIsJust :: Monad m => Maybe a -> (a -> m ()) -> m ()
 whenIsJust (Just x) f = f x
 whenIsJust Nothing  _ = return ()
 
--- | -- Often a more convenient argument order as compared to the not quite identical `maybeM`
+-- | Often a more convenient argument order as compared to the not quite identical `maybeM`.
+--
 -- @
 --    ifNothingM m d a = maybe (return d) a m
 -- @
-ifNothingM :: Monad m => Maybe a -> b -> (a -> m b) -> m b
-ifNothingM Nothing dft _  = return dft
+ifNothingM :: Applicative m => Maybe a -> b -> (a -> m b) -> m b
+ifNothingM Nothing dft _  = pure dft
 ifNothingM (Just x) _ act = act x
 
 maybePositive :: (Num a, Ord a) => a -> Maybe a -- convenient for Shakespeare: one $maybe instead of $with & $if