diff --git a/docs/design_guide.rst b/docs/design_guide.rst
index 5d965f9074..6f87ecf798 100644
--- a/docs/design_guide.rst
+++ b/docs/design_guide.rst
@@ -476,6 +476,8 @@ properties.
 +-----------------------+-----------------------+-------------------------------------------------------------------------+
 | ``distance``          | float                 | centimeters                                                             |
 +-----------------------+-----------------------+-------------------------------------------------------------------------+
+| ``proximity``         | int                   | non-unit-specifc proximity values (monotonic but not actual distance)   |
++-----------------------+-----------------------+-------------------------------------------------------------------------+
 | ``light``             | float                 | non-unit-specific light levels (should be monotonic but is not lux)     |
 +-----------------------+-----------------------+-------------------------------------------------------------------------+
 | ``lux``               | float                 | SI lux                                                                  |
@@ -504,6 +506,8 @@ properties.
 +-----------------------+-----------------------+-------------------------------------------------------------------------+
 | ``weight``            | float                 | grams (g)                                                               |
 +-----------------------+-----------------------+-------------------------------------------------------------------------+
+| ``sound_level``       | float                 | non-unit-specific sound level (monotonic but not actual decibels)       |
++-----------------------+-----------------------+-------------------------------------------------------------------------+
 
 Adding native modules
 --------------------------------------------------------------------------------