diff --git a/README.md b/README.md
index e231157..4a25063 100644
--- a/README.md
+++ b/README.md
@@ -107,6 +107,10 @@ Sample sketches have been included with the library as examples of how to use it
 
 More information on writing sketches for the Arduboy can be found in the [Arduboy Community Forum](http://community.arduboy.com/).
 
+### Using EEPROM in a sketch
+
+The Arduboy2 library reserves an area at the start of EEPROM for storing system information, such as the current audio mute state and the Unit Name and Unit ID. A sketch **must not** use this reserved area for its own purposes. A sketch may use any EEPROM past this reserved area. The first EEPROM address available for sketch use is given as the defined value *EEPROM_STORAGE_SPACE_START*
+
 ### Audio control functions
 
 The library includes an Arduboy2Audio class. This class provides functions to enable and disable (mute) sound and also save the current mute state so that it remains in effect over power cycles and after loading a different sketch. It doesn't contain anything to actually produce sound.