*/\r
uint8_t SerialNumStrIndex; /**< String index for the product's globally unique hexadecimal\r
* serial number, in uppercase Unicode ASCII.\r
- *\r
+ *\r
+ * \note On some AVR models, there is an embedded serial number\r
+ * in the chip which can be used for the device serial number.\r
+ * To use this serial number, define USE_INTERNAL_SERIAL to a\r
+ * unique string index number in the project makefile and set\r
+ * this value to USE_INTERNAL_SERIAL.\r
+ *\r
* \see ManufacturerStrIndex structure entry.\r
*/\r
\r