diff --git a/backends/GenerateCTest.hs b/backends/GenerateCTest.hs
index 54379bc..8555eaa 100644
--- a/backends/GenerateCTest.hs
+++ b/backends/GenerateCTest.hs
@@ -975,9 +975,9 @@ testInput :: Test
 testInput = TestList
  [
   -- Test that genInput passes on the calls properly:
-  testBothSame "testInput 0" "" (overInputItemCase (tcall2 genInput undefined $ A.InputSimple undefined []))
-  ,testBothSame "testInput 1" "^" (overInputItemCase (tcall2 genInput undefined $ A.InputSimple undefined [undefined]))
-  ,testBothSame "testInput 2" "^^^" (overInputItemCase (tcall2 genInput undefined $ A.InputSimple undefined [undefined, undefined, undefined]))
+  testBothSame "testInput 0" "" (overInputItemCase (tcall2 genInput undefined $ A.InputSimple undefined [] Nothing))
+  ,testBothSame "testInput 1" "^" (overInputItemCase (tcall2 genInput undefined $ A.InputSimple undefined [undefined] Nothing))
+  ,testBothSame "testInput 2" "^^^" (overInputItemCase (tcall2 genInput undefined $ A.InputSimple undefined [undefined, undefined, undefined] Nothing))
   
   -- Reading an integer (special case in the C backend):
   ,testInputItem 100 "ChanInInt(wptr,#,&x);" "tockRecvArrayOfBytes(#,tockSendableArrayOfBytes(^(Int),&x));"
@@ -1043,9 +1043,9 @@ testInput = TestList
    testInputItem' :: Int -> String -> String -> A.InputItem -> A.Type -> A.Type -> Test
    testInputItem' n eC eCPP ii t ct = TestList
      [
-       testBothS ("testInput " ++ show n) (hashIs "&c" eC) (hashIs "(c).reader()" eCPP) (over (tcall2 genInputItem (A.Variable emptyMeta $ simpleName "c") ii))
+       testBothS ("testInput " ++ show n) (hashIs "&c" eC) (hashIs "(c).reader()" eCPP) (over (tcall2 genInputItem (A.Variable emptyMeta $ simpleName "c") ii Nothing))
          (state $ A.Chan (A.ChanAttributes A.Unshared A.Unshared))
-       ,testBothS ("testInput [in] " ++ show n) (hashIs "c" eC) (hashIs "c" eCPP) (over (tcall2 genInputItem (A.Variable emptyMeta $ simpleName "c") ii))
+       ,testBothS ("testInput [in] " ++ show n) (hashIs "c" eC) (hashIs "c" eCPP) (over (tcall2 genInputItem (A.Variable emptyMeta $ simpleName "c") ii Nothing))
          (state $ A.ChanEnd A.DirInput A.Unshared)
      ]
      where
@@ -1068,7 +1068,7 @@ testInput = TestList
 --              defineName chanOut $ simpleDefDecl "cIn" (A.Chan A.DirInput (A.ChanAttributes False False) $ A.UserProtocol foo)
 
    overInputItemCase, over :: Override
-   overInputItemCase = local $ \ops -> ops {genInputItem = override2 caret}
+   overInputItemCase = local $ \ops -> ops {genInputItem = override3 caret}
    over = local $ \ops -> ops {genBytesIn = (\_ t _ -> tell ["^(", showSimplerType t, ")"]) , genArraySubscript = override3 dollar}
 
    -- | Show a type, simplifying how Dimensions are show.
diff --git a/checks/UsageCheckTest.hs b/checks/UsageCheckTest.hs
index d25c358..f012ae2 100644
--- a/checks/UsageCheckTest.hs
+++ b/checks/UsageCheckTest.hs
@@ -100,11 +100,11 @@ testGetVarProc = TestList (map doTest tests)
        [A.OutCounted emptyMeta (A.ExprVariable emptyMeta vA) (A.ExprVariable emptyMeta vB)])
 
      -- Test simple inputs:
-     ,(500,[],[tvB],[tvC],A.Input emptyMeta vC (A.InputSimple emptyMeta [A.InVariable emptyMeta vB]))
+     ,(500,[],[tvB],[tvC],A.Input emptyMeta vC (A.InputSimple emptyMeta [A.InVariable emptyMeta vB] Nothing))
      ,(501,[],[tvA,tvB],[tvC],A.Input emptyMeta vC
-       (A.InputSimple emptyMeta [A.InVariable emptyMeta vB,A.InVariable emptyMeta vA]))
+       (A.InputSimple emptyMeta [A.InVariable emptyMeta vB,A.InVariable emptyMeta vA] Nothing))
      ,(502,[],[tvA,tvB],[tvC],A.Input emptyMeta vC 
-       (A.InputSimple emptyMeta [A.InCounted emptyMeta vA vB]))
+       (A.InputSimple emptyMeta [A.InCounted emptyMeta vA vB] Nothing))
     ]
 
    -- This is a custom test because there's no instance of Data for Vars.
diff --git a/common/OccamEDSL.hs b/common/OccamEDSL.hs
index 23d0403..c8c4a35 100644
--- a/common/OccamEDSL.hs
+++ b/common/OccamEDSL.hs
@@ -211,7 +211,7 @@ inputCaseOption :: (Castable c A.Variant) => (A.Name, [ExpInp A.Variable], O A.P
 inputCaseOption (n, is, p)
   = do is' <- sequence $ map liftExpInp is
        p' <- p
-       return $ makePlain $ A.Variant emptyMeta n (map (A.InVariable emptyMeta) is') p'
+       return $ makePlain $ A.Variant emptyMeta n (map (A.InVariable emptyMeta) is') p' Nothing
 
 
 oCASEinput :: [O (A.Structured A.Variant)] -> O (A.Structured A.Variant)
@@ -355,13 +355,13 @@ class CanBeInput a where
   inputItem :: a -> A.InputMode
 
 instance CanBeInput A.Variable where
-  inputItem v = A.InputSimple emptyMeta [A.InVariable emptyMeta v]
+  inputItem v = A.InputSimple emptyMeta [A.InVariable emptyMeta v] Nothing
 
 instance CanBeInput [A.Variable] where
-  inputItem = A.InputSimple emptyMeta . map (A.InVariable emptyMeta)
+  inputItem = flip (A.InputSimple emptyMeta) Nothing . map (A.InVariable emptyMeta)
 
 instance CanBeInput (A.Structured A.Variant) where
-  inputItem = A.InputCase emptyMeta
+  inputItem = A.InputCase emptyMeta A.InputCaseNormal
 
 instance CanBeInput A.InputMode where
   inputItem = id
diff --git a/flow/FlowGraphTest.hs b/flow/FlowGraphTest.hs
index 21612f1..a4ff195 100644
--- a/flow/FlowGraphTest.hs
+++ b/flow/FlowGraphTest.hs
@@ -446,7 +446,7 @@ testAlt = TestLabel "testAlt" $ TestList
   ]
   where
     guard45 = A.AlternativeSkip m4 (A.True mU) sm5
-    guard67 = A.Alternative m6 (A.True mU) (variable "c") (A.InputSimple mU []) sm7
+    guard67 = A.Alternative m6 (A.True mU) (variable "c") (A.InputSimple mU [] Nothing) sm7
 
     spec8, spec9 :: Data a => A.Structured a -> A.Structured a
     spec8 = A.Spec mU (A.Specification m8 undefined undefined)
diff --git a/frontends/OccamTypesTest.hs b/frontends/OccamTypesTest.hs
index 5afba60..6f76286 100644
--- a/frontends/OccamTypesTest.hs
+++ b/frontends/OccamTypesTest.hs
@@ -605,11 +605,11 @@ testOccamTypes = TestList
     skip = A.Skip m
     jskip = Just skip
     sskip = A.Only m skip
-    insim iis = A.InputSimple m iis
+    insim iis = A.InputSimple m iis Nothing
     inputSimple c iis = A.Input m c $ insim iis
     inputCase c vs = A.Input m c
-                             $ A.InputCase m (A.Several m (map (A.Only m) vs))
-    vari tag iis = A.Variant m (simpleName tag) iis skip
+                             $ A.InputCase m A.InputCaseNormal (A.Several m (map (A.Only m) vs))
+    vari tag iis = A.Variant m (simpleName tag) iis skip Nothing
     outputSimple c ois = A.Output m c ois
     outputCase c tag ois = A.OutputCase m c (simpleName tag) ois
     testRep n r = A.Seq m $ A.Spec m (A.Specification m n (A.Rep m r)) sskip
diff --git a/transformations/PassTest.hs b/transformations/PassTest.hs
index 52aab9f..94d2fa7 100644
--- a/transformations/PassTest.hs
+++ b/transformations/PassTest.hs
@@ -566,14 +566,14 @@ testTransformProtocolInput = TestList
 
    ,TestCase $ testPass "testTransformProtocolInput3"
       (A.Alt emptyMeta True $ A.Only emptyMeta $ A.Alternative emptyMeta (A.True
-        emptyMeta) (variable "c") (A.InputSimple emptyMeta [ii0]) $
+        emptyMeta) (variable "c") (A.InputSimple emptyMeta [ii0] Nothing) $
         A.Seq emptyMeta $ A.Several emptyMeta $ onlySingle ii1 : [A.Only emptyMeta $ A.Skip emptyMeta])
       transformProtocolInput (A.Alt emptyMeta True $ A.Only emptyMeta $ altItems [ii0, ii1])
       (return ())
 
    ,TestCase $ testPass "testTransformProtocolInput4"
       (A.Alt emptyMeta False $ A.Only emptyMeta $ A.Alternative emptyMeta (A.True
-        emptyMeta) (variable "c") (A.InputSimple emptyMeta [ii0]) $
+        emptyMeta) (variable "c") (A.InputSimple emptyMeta [ii0] Nothing) $
         A.Seq emptyMeta $ A.Several emptyMeta $ map onlySingle [ii1,ii2] ++ [A.Only emptyMeta $ A.Skip emptyMeta])
       transformProtocolInput (A.Alt emptyMeta False $ A.Only emptyMeta $ altItems [ii0, ii1, ii2])
       (return ())
@@ -583,11 +583,12 @@ testTransformProtocolInput = TestList
    ii1 = A.InCounted emptyMeta (variable "y") (variable "z")
    ii2 = A.InVariable emptyMeta (variable "a")
   
-   onlySingle = A.Only emptyMeta . A.Input emptyMeta (variable "c") . A.InputSimple emptyMeta . singleton
+   onlySingle = A.Only emptyMeta . A.Input emptyMeta (variable "c") . flip (A.InputSimple emptyMeta) Nothing . singleton
    onlySingleAlt = A.Only emptyMeta . flip (A.Alternative emptyMeta (A.True
-     emptyMeta) (variable "c")) (A.Skip emptyMeta) . A.InputSimple emptyMeta . singleton
-   seqItems = A.Input emptyMeta (variable "c") . A.InputSimple emptyMeta
-   altItems = flip (A.Alternative emptyMeta (A.True emptyMeta) (variable "c")) (A.Skip emptyMeta) . A.InputSimple emptyMeta
+     emptyMeta) (variable "c")) (A.Skip emptyMeta) . flip (A.InputSimple emptyMeta) Nothing . singleton
+   seqItems = A.Input emptyMeta (variable "c") . flip (A.InputSimple emptyMeta) Nothing
+   altItems = flip (A.Alternative emptyMeta (A.True emptyMeta) (variable "c")) (A.Skip emptyMeta)
+                 . flip (A.InputSimple emptyMeta) Nothing
 
 
 testPullRepCounts :: Test