diff --git a/source/index.rst b/source/index.rst
index 2ef3ddd..f5f8780 100644
--- a/source/index.rst
+++ b/source/index.rst
@@ -8,10 +8,11 @@ Welcome to Pybricks's documentation!
 
 .. toctree::
    :maxdepth: 2
-   :caption: EV3 Modules:
+   :caption: Pybricks:
 
    parameters
    ev3devices
+   signaltypes
 
 
 
diff --git a/source/parameters.rst b/source/parameters.rst
index 67831bd..fc592cb 100644
--- a/source/parameters.rst
+++ b/source/parameters.rst
@@ -3,14 +3,18 @@
 
 Intro
 
-.. autoclass:: parameters.Color
-    :no-members:
 
 .. autoclass:: parameters.Port
     :no-members:
 
+.. autoclass:: parameters.Direction
+    :no-members:
+
 .. autoclass:: parameters.Stop
     :no-members:
 
-.. autoclass:: parameters.Direction
+.. autoclass:: parameters.Color
+    :no-members:
+
+.. autoclass:: parameters.Button
     :no-members:
diff --git a/source/signaltypes.rst b/source/signaltypes.rst
new file mode 100644
index 0000000..1da6960
--- /dev/null
+++ b/source/signaltypes.rst
@@ -0,0 +1,22 @@
+Signals and units
+=================
+
+Intro
+
+
+.. glossary::
+
+    time
+      TODO definition of physical quantity and units and :py:obj:`float` type
+
+    angle
+      TODO definition of physical quantity and units and :py:obj:`float` type
+
+    speed
+      TODO definition of physical quantity and units and :py:obj:`float` type
+
+    acceleration
+      TODO definition of physical quantity and units and :py:obj:`float` type
+
+    percentage
+      TODO definition of physical quantity and units and :py:obj:`float` type