diff --git a/public/style.css b/public/style.css
index 9a0cecf..50a5886 100644
--- a/public/style.css
+++ b/public/style.css
@@ -6,6 +6,11 @@ h1 {
     margin-left: 2rem;
 }
 
+.command-label {
+    margin-top: 1.5rem;
+    margin-bottom: 0.5rem;
+}
+
 button {
     font-family: 'Nunito', sans-serif;
     font-size: 1rem;
diff --git a/src/Command.elm b/src/Command.elm
index e7dd160..4dcaa53 100644
--- a/src/Command.elm
+++ b/src/Command.elm
@@ -6,8 +6,11 @@ module Command exposing (
     )
 
 import Html.Styled as HS
+import Html.Styled.Attributes as HSA
+import Css
 import List
 import Maybe
+import Svg.Styled as S
 
 import Space
 import Space.Content as Content
@@ -20,6 +23,7 @@ import Command.Components exposing (
       , toggle
       , choice
       , textButtonGroup
+      , commandLabel
     )
 
 {-| Interactions with the command controls outside the drawing space -}
@@ -54,6 +58,7 @@ viewBar {iterMode, baseContents}
             { incrementerDefaults | label = "# iteration frames" , min = Just 0}
             ChangeNumIterFrames
             (Content.numIterFrames baseContents)
+        ++ iterFrameKey iterMode.showIterFrames
 
 layerVisibilityControls : List (HS.Html Message)
 layerVisibilityControls
@@ -119,3 +124,25 @@ getIterFrameIDtoDrop {baseContents}
 getNewIterFrameID : Space.Model -> ID.TreeID
 getNewIterFrameID {baseContents}
     = ID.Trunk <| "f" ++ String.fromInt (1 + Content.numIterFrames baseContents)
+
+iterFrameKey
+    : Bool
+   -> List (HS.Html msg)
+iterFrameKey showIterFrames
+    = if showIterFrames
+        then
+        [
+            commandLabel "iteration frame controls"
+          , S.svg
+                [
+                    HSA.css
+                        [
+                            Css.marginLeft (Css.px 16)
+                          , Css.marginRight (Css.px 16)
+                        ]
+                ]
+                [
+                    IterFrame.showKey
+                ]
+        ]
+        else []
diff --git a/src/Command/Components.elm b/src/Command/Components.elm
index 5ee9551..4b788d1 100644
--- a/src/Command/Components.elm
+++ b/src/Command/Components.elm
@@ -1,6 +1,7 @@
 {- Visual components for controlling configuration -}
 module Command.Components exposing (
-        incrementer
+        commandLabel
+      , incrementer
       , IncrementerSettings
       , incrementerDefaults
       , toggle
@@ -15,6 +16,12 @@ import List
 import String
 import Css
 
+{-| Common heading for command controls -}
+commandLabel : String -> HS.Html msg
+commandLabel text =
+    HS.h4 
+        [ HSA.class "command-label" ]
+        [ HS.text text ]
 
 incrementer
     : IncrementerSettings        {- configuration -}
@@ -23,7 +30,7 @@ incrementer
    -> List (HS.Html msg)
 incrementer settings sendIncrement current
     = [
-        HS.h4 [] [HS.text settings.label]
+        commandLabel settings.label
       , HS.span [] [
             HS.button
                 (
@@ -99,7 +106,7 @@ toggle label sendToggle current
             = if current then "on" else "off"
     in
     [
-        HS.h4 [] [HS.text label]
+        commandLabel label
       , HS.button [HSE.onClick sendToggle, pressed, style] [HS.text labelText]
     ]
 
@@ -110,7 +117,7 @@ choice
    -> List (HS.Html msg)
 choice label choices
     = [
-        HS.h4 [] [HS.text label]
+        commandLabel label
       , HS.select []
             <| List.map
                 (\(choiceText, msg) ->
@@ -127,7 +134,7 @@ textButtonGroup
 textButtonGroup header buttons
     = [
         HS.div [ HSA.css [Css.marginTop (Css.px 10)] ]
-            ( HS.h4 [] [ HS.text header ]
+            (commandLabel header
                 :: List.map
                     (\(label, msg) ->
                         HS.button
diff --git a/src/Space/IterFrame.elm b/src/Space/IterFrame.elm
index 7bc877d..f8d4ec2 100644
--- a/src/Space/IterFrame.elm
+++ b/src/Space/IterFrame.elm
@@ -1,6 +1,7 @@
 module Space.IterFrame exposing (
         Def
       , show
+      , showKey
       , Mode
       , initMode
       , iterateShapes
@@ -102,6 +103,23 @@ showSkewHandle frameDef ifDef atts
         (atts ++ [SA.fill "magenta"])
         (G.Circle (cornerPoint frameDef ifDef G.BottomLeftCorner) 12)
 
+{-| Show a simple IterFrame to serve as a key explaining the IterFrame controls. -}
+showKey
+    : S.Svg msg
+showKey
+    = S.g []
+        [
+            show
+                (Frame.Rectangle 36 36)
+                (\_ -> [])
+                {identityDef | offset = G.disp 62 50}
+          , S.text_ [SA.x "0", SA.y "10"] [S.text "move"]
+          , S.text_ [SA.x "84", SA.y "10"] [S.text "spin"]
+          , S.text_ [SA.x "0", SA.y "96"] [S.text "skew"]
+          , S.text_ [SA.x "84", SA.y "96"] [S.text "scale"]
+        ]
+
+
 getTransform : Def -> G.Transform
 getTransform d = G.makeAffineTransform d.xBasis d.yBasis d.offset